Minecraft: 1.21.1
NeoForge: 21.1.209
Sophisticated Core: 1.21.1-1.3.85.1219
Sophisticated Backpacks: 1.21.1-3.25.9.1390
Sophisticated Storage: 1.21.1-1.5.11.1340
FTB Chunks: 2101.1.11

All mods in pack

Just holding an item and using the restock keybind will bypass the claim and take the items (tested with a server claim block interaction set to private, also happens with player claims). Happens for both chest and backpacks. Also works from controller but not I/O or Output ( nor Input, just in case )

Items in chest

After removing admin bypass, Cannot open chest

Can restock into hand from chest

Just for completeness, Open Parties and Claims also tested, version 0.25.6. Same results.

It's a shame that neither of these change player::mayInteract method which I am checking when these are run that would allow mods to not have to implement compats when they just need to check if player can interact with a block.

But anyway I have added compats for both of these and the latest release has those so closing the issue.