Yep, modular eats more VRAM the more stuff gets loaded, as it means most stuff gets loaded double - because the game (for whatever CM reason) loads files, even though they are already assigned already, endlessly into its memory.
Also one big texture into one erp consumes already a bit more than one small texture with external mipmaps.
I said that back in 2020 already (that's why I was never eager for stuff like teampackages, suits, garages etc. etc.).
If you use fomswaps you can atleast comment the original erp loading of the f1 teams out within their assetgroupfiles.
I think driversuits might be the same, but the rest not so much.
That is the downside of not having shared mips, like CM has with their chaotic system.
In the end, MoMods go against CM's "optimization" as we load files like F1 games did back 10 years ago.
Easier for modding but not easier performancewise. Also remember that CM uses 2k textures and f1 chassis mirror many parts. While we often use at least 4k, sometimes even 8k at fom. Same might apply to helmets, suits etc. etc.