I have already deleted half of the game saves from the system, load time is now 20ish seconds
and what is the .nx_save_meta.bin in the save backup folder? it wasn't there in previous versions
It saves information about the save container for restoring saves. Right now it's only used for the size since some games extend it as they go.
I did make a change that might be impacting boot. I went from memcpying to heap allocating the control data buffer and adding a move operator. The heap allocations might be what created the slow down from the previous version. I'd still be interested in the cache.bin file for testing and timing myself. I'm working with what I have. I have everything I own on my Switch.
Edit: It would also save me time from having to generate a fake one. That's another option.
@Muxi
May I ask what game you were trying to transfer? I just uploaded a save from my newer Switch, downloaded it to my older one, and it restored no problem for me. It might be something specific I need to look at. Also, if you're willing to try again, check if the log shows any errors. It's in the JKSV config directory.
Edit: I tried duplicating it again using Final Fantasy. I started the game, grinded a bit, sent it over to my other Switch through WebDav. It restored fine. On the other Switch, I played some more, defeated Garland, and let the bridge get rebuilt, repeat. It worked both times for me. Maybe it's a game specific thing? I'll attach pictures. Also, one of the Switch's is banned, so it can't be because of NSO sync either.
Edit 2: I've tested this with multiple games, FF, Minecraft, New Pokemon Snap, and both Zelda titles. I can't duplicate it. The only thing I can think of is to try it again and post the log file. It should catch whatever is happening. The log is cleared at each boot though.

