Lots of vim users do that too, in fact the ADM-3A terminal vi was written on had ctrl where caps-lock is now and escape where tab is.
- the : key to the right of the 0 on the number row, no Shift needed.
- the Enter key to the right of the P.
I've made both changes to my keyboard layout and, not surprisingly, it's quite convenient.
Downside is, you'll have to move the original keys somewhere else. But since I already intended to totally reshuffle all the non-alpha keys for RSI reasons, it wasn't an issue for me.
The one thing I wanted the most was to avoid any long presses. Everything that requires holding a modifier, even if I do it touch-typing style, with the opposite hand, is unpleasant (to me). So, besides moving most of the punctuation characters to lowercase positions, I also switched to sticky modifiers. (keyd might have some flaws wrt sticky modifiers, and they... get stuck. Not when I want them to be. I might try to go back to XKB.)
Regarding the home-row modifiers, I've only tried moving Control there. I always ended up triggering it by mistake when typing, because when you are typing fast, there is an almost unavoidable overlap in certain sequences, you press the next key before fully releasing the previous key. Some people advice practicing, other software provides various options with timeouts, it's a rabbit hole of work-arounds. So I settled with sticky modifiers.