## This is fine, provided you obey a few rules

While a MWBC serving a mix of 120V and 240V receptacles certainly may *look* strange to the uninitiated, or those who interact with electrical systems in a professional capacity yet are not trained to the full panoply of NEC requirements, this setup *is* Code-legal in the 2017 NEC, provided the breaker protecting it provides *common trip* functionality, which all full-width two-pole breakers do these days.  This is laid out in NEC 210.4(C) Exception 2:

> **(C) Line-to-Neutral Loads.** Multiwire branch circuits shall
supply only line-to-neutral loads.

> *Exception No. 1: A multiwire branch circuit that supplies only one
utilization equipment.*

> *Exception No. 2: Where all ungrounded conductors of the multiwire
branch circuit are opened simultaneously by the branch-circuit overcurrent device.*

With the upgraded GFCI requirements in the 2020 NEC, this setup requires a two-pole GFCI breaker instead; however, that lets you split the 120V receptacle here to balance the load better, and means that all receptacles on the circuit are GFCI protected, which is also a plus.

However, despite the above, there are a few caveats set not by the NEC itself, but by the limitations of available hardware.  First and foremost is that two-pole *dual function* breakers (that provide both arc-fault and ground-fault protection) just aren't made, so if you were doing this in a location where AFCI was required, you'd need to have a two-pole GFCI breaker in the distribution panel for this circuit feeding an auxiliary distribution panel with a two-pole AFCI breaker in it.  (Of course, if you're feeding more than one circuit of these, you can use a bigger GFCI breaker to feed a subpanel with multiple AFCI breakers in it.)  Also, some more modern AFCIs (GE MOD 3 CAFCI breakers, most notably) are incapable of providing common trip overcurrent protection to a multiwire branch circuit due to design tradeoffs they made in order to ease installation in shared-neutral situations generally.  This isn't an issue if a single MWBC is used as the two-pole GFCI breaker provides common trip overcurrent protection for the circuit at the correct breaker rating, but is a showstopper in a multi-MWBC setup, as the GFCI breaker gets enlarged (up to 50 or even 60A) in order to feed the loads from the additional circuits.

Other than that, you'll need to treat the downstream wiring with the same cautions that are required for any other MWBC: namely, the hots and neutral for this circuit need to be grouped in the panel as per NEC 210.4(D) and 200.4(B) (a ziptie will do) and the neutral must be pigtailed to the 120V receptacles so that removing a receptacle doesn't leave the neutral floating downstream, as per NEC 300.13(B).  Last but not least, in your situation, while most of the primary tools can be on a single MWBC, you'll want dedicated circuits for stuff that is running at the same time that a tool is (most notably, the dust collector).