Good question. Some of us may wish to recoat the primary down the track. I can tell you that it's a cleaner removal in my configuration, compared to its stock configuration, permanently bonded in three places by black silicone!
Personally, I'm not after any "popping" action on my RC mirror... it's there to stay unless it's essential that it be removed. As you know, the beauty of Velcro - break the seal and reuse. I might try fewer Velcro dots on next install later in the year, following my mirror recoat. This should make for easier removal, but at the expense of primary mirror support... I'm not sure. The dob/newt guys can do the calculations. You can also buy different Velcro dot sizes to adjust tension (e.g. 16 or 22mm).
Regarding the use of silicone to secure optics, I just want to repeat some A+ advice I came across from Australia's Mark Suchting, one of the best:
" ... from my own direct experience - Silicone is absolutely capable of warping optics -it is only warping on a sub -micron level we are talking here . This is my own practical experience of testing optics on and off silicone mounts in a highly sensitive bench star test . Diagonals are also susceptible to warping if not mounted just right if silicon [is] used. I would always recommend optics to be free floating both from the edge and back for the best possible level of support without possibility of induced strain at different angles of altitude. It is certainly possible to pull off a silicon mounting but it willl rarely be as good as a free standing optic and can certainly end up much worse if it is not done right."
I believe that I have now arrived at a 'free floating', or 'free standing' system at the back - and edges, by removing the black silicone, mirror clips and instead using Velcro
