As long as you're not damaging the bellows and not vignetting the image, I see no problem with the lens making contact with the bellows occasionally. If the Chamonix accepts a recessed board, that might help a bit (the trade-off being that you have use a tool to manipulate the lens settings in a recessed board; I use the tip of the cable release).

However, if you can get your hands on a good 90mm f/8 with a large enough image circle for you you may appreciate the weight reduction (I have both the Nikon SW and the Schneider SA in f/8; the Nikon has a larger image circle and gets used for architecture shots more). I would never want to lug around the larger f/5.6 models.