Is there an upper limit on the usable VRAM on Airs, or is it just tied to RAM size minus a bit for the OS? Just got a 24GB Air M2 and your comment made me wond

Is there an upper limit on the usable VRAM on Airs, or is it just tied to RAM size minus a bit for the OS? Just got a 24GB Air M2 and your comment made me wonder if it was capped at n amount of VRAM, or if it's just that Air's now can have 24GB of ram compared to 16GB with the M1 Airs?