The save state thing was actually my own fault or something, it works now, only Dolphin fires the save state load very delayed but that's just Dolphin i guess.
For modding Brawl / PM it's not very useful if you already use Skip Strap and Skip to CSS codes, since the save-state load will always load the same assets, only when you enter Stage screen and go back it updates etc. so save states never load updated content - you have to load them manually and for that pressing Tab for speeding up emulation is a bit more helpful imo.

Still, thank you SO MUCH for this tool!

This tool is very useful, but does it check actual dates..?
As in does it not overwrite if the source file has an older date?
If that's the case, there should be a setting to toggle "always mirror" i.e. make the SD contents equal to the source no matter what dates.
Also i'm having trouble getting savestates to work, when i make some in the emulator it doesn't find them - no matter if started from VSDSync or not.