Dunno, maybe of interest. Came from a discussion outside ACC re: Gyeon products (new and existing) and the topcoats in each:

From Jeremy at Gyeon

Bead - Topcoat in pro-only Durabead
Flexi - Topcoat in pro-only DuraFelx
Phobic - Topcoat in pro-only Gyeon Mohs+
Skin - Topcoat in Gyeon Syncro
Booster - Topcoat for any coating, sold by itself

Booster is the less concentrated version of Bead
Skin is the less concentrated version of Flexi

Comparing Flexi to Bead and Phobic would look like:
- Flexi beads like Bead
- Flexi is not reacting with the surface like Bead, but it`s being an additional layer like Phobic
- Phobic is much more hydrophilic compared to both Bead and Flexi
- Flexi is super slick - much more than any of the others
- Phobic is a quartz/ceramic coating
- Bead is a fluorine-based reactive top coat
- Booster is fluorine based topcoat, reactive I`d guess like Bead but not as potent
- Flexi is silicone based.