I used to do approximately this, from maybe the mid-90s to 2015-ish, but finally that keyboard died (RIP dear friend) and I find that it doesn't work properly on any keyboard I've found since.
Not quite the side of my palm, but the joint where my pinky meets my palm. My hands are relatively large, dunno if that's relevant.
I should put more work into buying a keyboard that it does work on, I think using my finger for Ctrl might be starting to cause RSIs in my middle-aged hands.
I guess I'll also add that for me it's a bigger deal when gaming than when using CUA. That Ctrl button is the one true place to put crouch, dangit.
