I did my Spartite installation some five or so years ago, the instructions were very clear to me to not coat the mast, only the collar... I wanted to have, and got a very water-tight seal, as the low halyard exit boxes on the CS 36T made any type of traditional boot very difficult to work. I rank Spartite as one of the all-time great products.
I just pulled out the Spartite instructions and stand corrected. They only recommended coating the mast with release agent if the boat has hydraulic jacks at the mast step, a bendy spar, or if movement is desired without bonding the mast. They also state that the seal will be better if the spartite is bonded to the mast (of course). Based on my search of this forum, it seems that some boats seal tighter than others with Spartite. Initially I used the caulk Spartite recommends ("Life Seal by Boat Life") to seal the perimeter. It seemed to work briefly, but after a couple of windy outings, I noticed water penetrating. The funny thing is, a couple of weeks ago, I was using some Silicone for another project. I noticed the Silicone insructions said "unlike other caulks, Silicone retains it's elasticity". I thought..."Hmmmm, I wonder if that might solve the Spartite problem?". In the back of my mind, I thought there must have been a reason I didn't use it when I installed the Spartite, but thought "Well, that didn't work, so what do I have to loose?". I cleaned off the Life Seal and installed Silicone. It seemed to keep the rain water out for a couple of weeks (without sailing), but is now leaking like a sieve! In reviewing the Spartite instructions, they state "Do not use Silicone, it will not bond to Spartite".
! Anyway, the difference in results with Spartite between boats/owners is interesting. Glad it's working for some! It certainly wasn't worth the effort for me. I'll probably re caulk with Life Seal and reinstall the boot I was trying to eliminate!