I am sure QG will comment, but the problem with the bellows is that it's minimum extension is kind of long; 73 mm. At least according to http://www.hasselbladhistorical.eu/P...areBellows.pdf
So it would be good if you are working very close with high magnifications. But not useful if you're working at moderate distances like within a foot/several cm's or so.
Exposure adjustment info is also at Hasselbladhistorical.