You're in EMT!
All the EMT is a legit grounding path. You don't even need a ground wire, the EMT shell is the ground.
"Oh, but that doesn't seem like enough" is a thing I often hear. In your case, you have redundant EMT paths to all locations but the last, even if you ran no ground wires at all.
Note that if you do run a ground wire, you are required to tie that to the metal junction box, not the receptacle. You do not wire this like plastic boxes. However once the metal box is grounded, the recep can pick up ground via the yoke (or mounting screws if it is self-grounding).
The back of every metal box has a hole tapped #10-32 for a ground screw. The only place you need to use it is at the first box. You may need a ground clip there, as extension boxes often overlook the ground screw hole.
Watch your box fill. Your 2-gang boxes with 4 wires in, 4 wires out and 2 receps will need 8 wires + 4 for the yokes = 12 "wires" x 2.25 = 27 cubic inches, or 29.25 if you insist on running ground wires. A common 4x4 steel box (21 c.i.) and domed cover (6.5 c.i.) is mighty close.
I do the 2-circuit thing all the time, and I have lots of places where I have to stack an extension box because I didn't think ahead and use a 4-11/16" box (slightly larger but twice the cubic inches).
For two GFCI devices abreast, don't waste your time with 4x4 boxes. I recommend 4-11/16" square boxes (reasonably priced at the electrical supply) and a domed cover. These domed covers are big enough that you won't need to mutilate the Decora cover-plate tabs.
Oh no! Unrelated circuits passing through EMT!
LOL I don't care. Totally routine.
This boils down to your careful wire marking. This sort of thing is why I own 10 colors of THHN wire. If you want to get er all dun with 2 colors of THHN,
Nobody says you have to use black & white. Gray is also allowed for neutral and hots can be any other color but green. So go to a real electrical supply and buy 1 spool of gray and 1 of blue or whatever floats your boat. (Home Depot won't have gray, purple, pink or brown).
Get your 5-pack of colored tape! Remember, with individual wires in conduit, there's no remarking to change purpose. A white wire with black tape is still a neutral. I like to mark wires with their partner's color.
Use stranded THHN and pigtail all your receps.
It installs even easier than solid wire. The reason for the pigtails is so you can use solid wire for the lands on the receptacle screws. I pigtail nearly 100% of my receps, simply because I don't want to fidget with 8 shepherd's hooks and fitting receps to cover while up a ladder or in some stress position. Assemble the lid and pigtails at a comfy workbench, then up the ladder, 4 wire nuts and done :)