Actually, someone found the Mode Connectivity in ViT (a quite larger NN I thought). Not sure if LLFC will be still satisfied on ViT but it worth a try. As for the pruned network, I believe that pruned network still holds the LLFC. (I think you refer the LLFC as "weak additivity", right?)
Great comments! Actually, we have made some progress in linking task arithmetic with our NeurIPS 2023 results and we are working on a new manuscript to introduce our new results. Hope our new paper could be released soon.