Chainy:What do you think about the suggestion that Sergio Pokrovskij makes in ReVo: gepatrANo, geavANo

I always found that form long-winded and slightly ridiculous, myself. As far as I can see it's not in use very much either, although that could be because a singular gender-neutral form is actually very rarely necessary.

What do you think about the suggestion that Sergio Pokrovskij makes in ReVo: gepatrANo, geavANo etc...?

I think there's a lot to be said for simplicity - can be better to avoid making larger, meaning-packed constructs, when simpler ones will do. Using non-standard "geavo" has less morphemes in it, and so the meaning is more immediately apparent than the technically grammatically more okay, but actually super-rare "geavano", with its 3 morphemes.