There has been much discussion about mast wedges and alternatives among Freedom owners. To the best of my knowledge, all Freedoms have FRP partners, and all but a few very early ones have carbon fiber masts.
Freedom originally used hard polyurathane rubber wedges. They were long gone when we purchased Flutterby. In our case, there was Spartite poured around our masts. It was very difficult to remove the masts, due to badly gouged partners that the molded rubber "locked" into, plus some molding problems leaving a lip below the partners on the less accessible main mast. The spartite wedges were destroyed getting the masts out.
We repaired the fiberglass around the partners and re-painted it before we poured our replacement. We used mold release on the partners but not on the mast. Our partners are tapered so the poured part is a wedge.
If the partners were cylindrical, or if I couldn't fair and paint them smooth I would probably do something else instead like traditional wooden wedges..
We did not use Spartite because it is expensive, and it is also reported to be too soft for a freestanding mast. Instead we used a harder PU rubber compound called PMC-790.
You can read more about it on this thread from the Freedom owners forum.
http://freedomyachts.org/viewtopic.php?f=9&t=47
I did my homework....but haven't passed all the tests yet: The masts have been up for less than six months. They haven't fallen down or leaked (We used additional bedding above and they are clamped in above and below, so there is no way the wedge could work out of the partners). But no sailing to date (still working on sails), and no attemps to remove the masts either.