I'm not finding any place where people share their keymap config (if that's the right way to refer to how you've configured which key has which actions bound to it), so here goes mine - and I hope to have feedback and to be inspired by yours, as well!
From some awesome inspiration, I updated the setup :-) thanks!
I moved the layer switcher to the left hand, and moved backspace to my thumb, so I don't strain my pinky so much.

I moved the arrows to right under my right hand... and added a button to make the switch to this gamer layer permanent. So basically, to go from layer 0 to layer 1 permanently, hold left thumb button, tap right thumb button. Tap left thumb button to switch back to layer 0.

And I added a num pad, also right under my right hand, where I'd expect it.

original:
I just got my first mech keyboard with fewer keys than a 'regular' keyboard, and set it up this way:

with the TG(1) switching to layer 2 for gaming/some extra symbols:

and the home row is modded to GASC like in https://precondition.github.io/home-row-mods#how-to-use-home-row-mods with 160ms tapping term.
I am mostly struggling to get used to this way of typing and I still spend a lot of time on finding symbols, or correcting extra or missed keystrokes. But, I'll try to update this when I have more experience.
Critique away!
Oh, that's a nifty way to think about it, modify with one hand and map it to a situation as if the other hand was where you'd have it, e.g. with the arrow keys!
Have you tried home row mods? In theory, it sounds good...
What do you mean by home row mods? Layer switching happens on my home row, when holding those keys, if that's what you mean.
Ah yes, that's what I meant, but putting heavily used modifiers like shift, Ctrl, alt under those fingers and mirroring the setup between left and right hand, trying to make the most out of those 8 keys where you don't need to move your fingers for.
Ooh, interesting, I guess the layer modifiers are kind of the same thing indeed. I have too many layers for that so I don't think I'll fit that in, but I like the idea.