The Velocity is an RDA? That should do 100% VG just fine ;D
Most RTAs should do fine with 15/85 provided it’s wicked correctly - If you get dry hits, you could add a little bit of distilled water… Start with a couple of % only. Or you could just add a little more PG…
RDAs usually have no problem with pure VG - Tanks need to wick differently, so there viscosity is a consideration… You’ll probably have better flavor with more PG in it…