scientists advise looking for water first

but never one drop of rain on Arrakis or anywhere else for that matter

I would hazard a wild guess and say filter for g types only as that's where Kepler or webb may focus
then again if silcone based life is a thing (well the bonds are there) water may not be a required solvent and liquid methane may be a suitable alternative so systems with methane worlds may be worth focusing efforts?
(as the old Cambridge mob are quite scientific when I comes to this game)
(those old raxxla mkI pedals were great but discontinued

)