I'm working through an algorithm that uses this partial Kronecker product formula for each tensor of an MPS in v3. Matt's solution (see link) works great for individual ITensors. Unfortunately, I can't seem to get this working the same way for the tensors of an MPS. I get an error about "different index structure".

I've tried brute-forcing the tensors to have the exact same indices several different ways with no luck. I suspect that this error has something to do with overwriting the MPS tensors as I compute them; is there a "correct" way to do that? I suppose I basically want to build an MPS from scratch, given that I know what the indices should be and what the tensors should be.