Most ways of doing that won't be to code. It would be better to add it as a separate circuit.
All they care about is that you can't run more current down a wire than it's rated for.
[0] https://getneocharge.com/products/neocharge-smart-splitter
Each leg of 240 is only 120, so it'd probably work.
Don't do it! But if you do it make sure it's breakered correctly and use a AFCI/GFCI combo breaker.