I like this.

Might consider switching the Delete Key and Art 5. Art 5 could be like an F13 (like on Novelkeys TKL)

I have a TKL at home with a separate Num Pad on the left (I hate giving up the mouse to put numbers in). Am building a Rekt1800 ( I know, still right handed) for work but could be persuaded to route it to someone else for an ideal southpaw.

What are your plans beyond the layout?

Incline? Plate? PCB (Solder/Hotswap)? Weight? Colors? QMK/VIA?

FWIW, I really would like a true full size (i.e. cursor keys and PUp/PDown/Home/Insert/Delete on the left between the NumPad and primary keys). That would be my ideal board. I tried an Epomaker 96% Southpaw and didn't like the tight grouping of keys.

I wish you luck on your project and hope to see your updates on progress!