Is it possible if you select a multiple exposure to shift the centre point so you can bias to expose to more frames on one side than the other of the "normal "exposure?
I'm pretty sure I've done that. Selected a 3-shot bracket at -1,0,1 but had EV set to -1, so the shots came out as -2,-1,0.
Thank you , I had not tried that, that is the answer along with suing the right display mode to show the offset.