According to RB :
I don't believe that it is a code violation. I don't like to see
multiple breakers feeding one box but the last time I looked it was
within what the NEC permitted for 120 volts.

Look a little more carefully w.r.t. "same strap".

The CEC is pretty anal about insisting on single disconnects for all
power feeding a box. Failing that, you need metal partitions between
sections and/or seals, labeling, and "unlikely to be accessible to
non-licensed personnel" - the latter won't generally fly in residential
installations.

Ie: residential main panels in Canada have metal partitions between the
main feed connection/main breakers and the branch breaker section. Most
panels have two covers so you can open the branch breaker section and swap
breakers without exposing the main feed.

While the US NEC is somewhat looser in this regard than the CEC,
they do insist on single common disconnect for all circuits feeding
the "same strap". I've never been 100% sure what "same strap" means
in this context, but it should cover this because the two circuits
are on the same _device_ (split outlet), especially if they shared
neutrals (only cut the hot jumper, not both. If you did that, I _hope_
that the two hots are on opposite panel legs, otherwise, you could
melt the neutral without tripping a breaker).

I'm sure that a US inspector would fault it even if it wasn't quite
a code violation if you didn't have a very good reason for it. Because
the next person opening it may not be as careful as you.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.