Do I miss something? Whanever I am near "main hub" with a lof of different items stored nearby on shift+C pressed some of the items dropping on the ground making me running around with "F" pressed during minutes. As you understand it is VERY annoying. I am playing with few mods that adding stackable version of items and changing stack sizes.

It drops items on the ground when your inventory is full and it can't return them. Do you have a fuel or ammo limit set? It might take fuel out of the machine's to stay below the limit.

I am understand that it dropping on inventory overfill. In my settings on the right panel of the inventory window I have 1 stack for ammo and fuel. I dont actually care about that. Do you think it causing the problem? Anyway I didnt have any fuel or ammo in my inventory after shift+c, and even if it takes 1 stack of coal, shift+c on overfill is trying to take so much that my trash slots are full. If it is a bug I am ready to assist.

You could try disabling the limits for shift c (two checkboxes)

Did you have stuff in your trash slots when pressing shift c? I think there was a bug when you manually put stuff in there. Setting a autotrash rule for the items instead fixed this.

I will try to disable checkboxes and look if this will happen again with empty or manually trashed slots. However rn my map becamed to scatered and amount of items moved through shift+c is very low. I will update here if I will experience this behaviour again