Ok, I see I must have been fiddling with the script and pushed it out by mistake. Basically, the kits/boxes shouldn't stay attached from the hotkey (as the boxes are replaced to fix the weight bug) when there isn't a replacement box on the back already ... however, removing the box from the attachment point manually (right clicking and clicking remove) will replace the box with a non-bugged one, for now until I push the next update. The weight bug appears from something in the core game. When containers are attached, their weight begins to match the player weight, even once it's left their inventories. It's quite odd. My mod has a script that does it's best to replace these, but the moment they become attached again, the weight bug reappears.

I think I've found an even better fix at this point that gets rid of the attached container bug altogether, after a dive into the java classes.

The weight bug seems to be fixed, but attaching a First Aid Kit to a backpack still renders all the items inaccessible.

hey the mod seem's to work, but i cant see the items visually attached to the backpack

having the issue of the attached first aid kit :/

I have also been having a similar issue, after attaching the med-kit from by back to my bag, it locked several important items within the medical kit. haven't found a solution to the issue in game however

Edit: quitting the game and re-entering with the Med-kit in my secondary fixed the issue, perhaps the bug is somewhere between the swap between the "on back" state and the "attached" state?