Compressing the suspension, or any spring, fatigues it. It is best to leave
it as unloaded as possible. Having the suspension fully extended is less
taxing on the springs and will help them live longer. The spring performance
could be anywhere from subtle to obvious but the length of time a spring is
compressed does affect its usable life. Certainly the more it is compressed,
the more strain there is on it and the faster it fatigues. Support the bike
on the centerstand and under the pivots for the front swingarm. If you need
to roll it around, roll it off the centerstand and do it. Having the rear
wheel 8~10 inches in the air and the front only MMs in the air does not sound
terribly stable to me. I would worry more about it falling over than anything
else in that forward canted position.
RSRBOB