I don't think this is the problem since I removed the Crafttweaker script and I'm still not getting overencumbered with an inventory full of the original supplementaries sacks, but just in case:

I'm trying to use Crafttweaker to add overencumbering/shulker_exclusion to the dyed sacks from supplementaries squared, working in a mod environment with just supplementaries, supplementaries squared, and then a couple utilities like REI, mod menu, and jade. I added the dyed sacks to the overencumbering tag to no effect.

In the process of testing this I realized that the original sacks weren't giving me overencumbered either, in creative or survival. I removed the Crafttweaker scripts and reloaded to put it back at the original tags, and it's still not weighing me down.

I could have sworn that when rooting through the source code I previously found the bit that did the math on what's in the inventory to apply the effect, but I'm not seeing it now when I search "overencumb", but that might just be me not hitting the right search term.

Thank you for all the amazing work! Supplementaries is one of my Always mods that I can't play without, you've got the great function and some fantastic aesthetics to boot.

Ah, I am an idiot. No they are not.

For the dyed sacks being able to nest, will this count as the bug report or should I post it to that mod's page?

I forgot to tag those I'll fix

Whelp. Sadly that didn't seem to be the issue. I installed manually from CurseForge but it's the same issue. I don't know what could be interacting with it, with the exception of Supplementaries Squared I have played with the mods installed before.

I did have Rustic in but as you can see I disabled it and then created a new world, just in case something in the original testing world was causing the problem. Just in case the code for overencumbering runs when items are picked up vs in the inventory I switched to survival before picking them up. I also drank a weakness potion to make sure that there wasn't something wrong with statuses in general.

As a side note, while the dyed sacks don't go in shulkers they do go inside the original sacks and the other dyed sacks.

Are those sacks full?

thanks!

you have latest version? idk i cant replicate, i can geet it from supp squared sacks normally

Ohhh, I was building it off the curseforge launcer and I did have to get another mod manually (owo I think?) because it was giving me the wrong version. I'll double check when I get home but I'll bet that's what it was.