To my understating, the safe amount of how much RAM to allocate in the vmparams for Java 7 and 8 was half of available VRAM on the system, and for the total estimated VRAM usage not to go over that, preferably with some wiggle room (used SMOL to figure the total).
The youngest part in my PC is the now a ten years old NVIDIA 970 (yes, yes, but at this point a complete overhaul is needed as just swapping the card won't cut it, but I currently cannot justify the cost), which gives me 8gb VRAM (or 7.5gb more accurately), which means 4gb allocation.
Currently I have 3,800 GB VRAM worth of mods installed, and according to Console Command overlay I have 500-600 of free VRAM remaining, still in green letters. With MJ23 the game runs as well as expected considering the old hardware, with the only really problematic but bearable IMO spots being the startup loading times and the modded 800dp battles when there are allies on my side.
The question is, can MJ23 allow me to go even further over that, if only a little bit?