We are at the cusp of service upgrades being obsolete. Technology Connections has a whole video on the topic, but you don't need a SPAN panel to do it. More tech is coming up fast.
Are you completely married-for-life to the idea of your EVSE having a receptacle and not being hardwired? Because the receptacle forces you into sad old tech.
An EVSE is what people call a charger. It's much less, but much more.
EVEMS is already solved
From the first two comments it seems there's a knowledge gap. Let's fill that in so you can think properly about products. That thing on the wall is NOT a charger. Really.
It is just a gateway. It passes AC power straight through onto the L1 and L2 pins on the J1772 or Tesla connector. Its job is to place a 1000 Hz square wave on the "CP" control pin. The duty cycle tells the car the safe amperage it can draw. The actual AC/DC conversion happens onboard the car in a literal battery charger the size of a suitcase and water-cooled. It obeys the CP signal dynamically on the fly.
Gee, that'd be awfully handy if we're trying to do energy management!
Yeah. That was the entire point. SAE is the auto manufacturers' standards-setting organization. They knew "needing a service upgrade" would be a sales killer, so they built J1772 on purpose to make things like this easy (and coordinated with UL). Not their first rodeo; this is their fourth from-scratch attempt at an EV standard.
So yes. They intended from day one for EVSE's to be able to talk to CTs and use the square wave for EMS. Or let Multiple EVSEs dynamically share a fixed block of power. Or both at once. They designed it to make this easy.
Tesla uses J1772 in a different connector shape (an adapter is made only of copper and plastic), and Mennekes does the same with 2 more phase pins added (again, an adapter of copper and plastic will let an American J1772 or Tesla can charge at a Mennekes station, and all that square wave stuff will work correctly.)
That clunky old "EMS" tech is for water heaters.
I use that term laughably, because really, they're old Load Shed devices with a new sticker slapped on them. They're for a water heater, hot tub or our fathers' forklift battery charger. Selling them for EVs is almost deceptive since they totally ignore EV tech and do it "the hard way".
And worse, they're needlessly costly because they need the CT clamps and a huge contactor that is rated to interrupt under full load... because they just don't have a smarter way to do it.
So yeah. Forget those old things, at least until you get a hot tub.
Readily available models of modern EVEMS
In the American market, avoid the Emporia EVSE + VUE energy monitor, at least for now. They implemented it foolishly on the software side (because they were chasing the wrong feature-set), so it doesn't meet UL standards.
Another product I've heard good things is the Wallbox e.g. Pulsar Plus. This one supposedly does this with multiple EVs at once, so you can have three EVs plugged in, all grid-limiting.
Elmac and SimpleSwitch seem to have solutions. C'mon Tesla!*
Over in Europe they have the Myenergi Zappi doing the same thing, wired or wireless. The Zappi also solves the PEN fault problem they have over there.
And all these units can do "Solar capture". A lot of people don't have net metering, they get paid a penny a KWH for their solar yet must pay 15 cents a KWH to charge their EV at night. These products can sense when you're overproducing solar and divert exactly that much into your car's battery. And the Emporia is fine for that since it's not a safety system.
One simple trick - having the actual battery charger be on the car and obey a square-wave signal on CP - enabled so much smart tech it isn't even funny. The EVSEs aren't particularly complicated - you could build one with an Apple II. It's easy to understand. It makes the on-the-car battery charger complicated to engineer, but not much to build, so the smart design is practically free. Genius... go SAE!
And proof is that Europe didn't really find a way to improve on it. They just added 2 phase wires and left the CP/PP protocols alone.
Onto your Load Calculation
So, Sunnyvale's worksheet is not a genuine, valid NEC Article 220 Load Calculation. It has a lot of "stand-in" numbers that are "fanciful". For instance, the electric tankless water heaters come in anywhere from 7kW to 22kW; you can't use 15kW as a "stand-in" LOL. Likewise we just placed EVSE at 0kW, and they can range as high as 19kW. Sometimes you just can't use a unit like Wallbox or Empori
So that dryer number isn't right; if your laundry room has a dryer vent to outside (dis-preferred in newer tight homes), you need to allocate 5600W there because that is the power of almost every old-school electric "shove the wet air outside" dryer. Likewise tanked resistive water heaters are mostly 4500W with a few 3840W units for trailer homes.
So I don't know what to do with that sheet; obviously Sunnyvale can make it legal, but it feels like it didn't really receive the engineering scrutiny that the official NEC Article 220 methods receive. I would prefer the alternate method in 220.82 for dwellings which is similar to Sacramento's. (the standard method in Article 220 is a catch-all for everything from Nike Ajax launch sites to auto assembly plants; it's not wrong for dwellings, just unnecessarily complicated). The alternate method usually produces more favorable numbers, too. Most municipal worksheets (the ones which follow NEC, that is) use the alternate method.
Splitting the dryer circuit
I know automatic dryer splitters are popular; however, while they have a certain "gadget-buying appeal", they aren't actually required. There are two workarounds depending on your discipline and your panel.
First, there's a thing most people call a "generator interlock". The manufacturers don't call it that - quite on purpose! It's to interlock any two breakers you don't want on at the same time. Not every panel manufacturer makes side by side interlocks, but those who do sell them for around $30. You have to flip it to use one or the other. This is good when you don't have good family coordination.
Second, if you can self-manage not drying and charging at once, here's a little-known fact about NEC. You know general-purpose 15-20A circuits can have multiple receptacles - so can general-purpose 30A circuits! Dryers are not required to be dedicated circuits, and you can defend a 30A socket in garage or parking spot as "general use" - the spouse is thinking of buying a kiln. So the only gotchas here are #1 you can't extend a 3-wire dryer circuit with NEMA 10-30, and #2 a new outdoor/garage socket in a NEC 2020 state needs GFCI, so that's a $100 breaker you'll be popping for. But it beats an automatic switchie-doo, as well as the very hokey cable routing we typically see with switchie-doo's.
* Tesla has Power Sharing since Rev 2. Now that Power Sharing is wireless on the Rev 3, all you need is a frob that sits on the panel with two CTs and acts as the Power Sharing "master". And that would just work with existing Wall Connector Rev 3, including the J1772 model. And ClipperCreek, you put a very clunky but very public protocol for your Power Sharing scheme; same deal - a frob in the panel with CTs that acts as master. Anyone could build that box; we don't need your permission since you opened the spec. There's a small isolation issue, but solvable.
