Hi Hanro.

I have a bit of 810 envy and your question perked my interest.
Bracketing is something I plan on trying out shortly, so thought I'd look up a bit about it.

Looks like, from reading discussions about the 810 and bracketing on other forums, that the solution to bracketing in Mup mode is by using a remote and taking each shot individually and keeping count of the shots yourself so not to start a sequence again by shooting too many times. I did see that if you shoot in Live View, that the mirror is always up, but that you then have an issue with EFC.

This is just a brief rehash of what I read and not from any actual experience. I hope to learn more when those in the know get a chance to reply to your question.