frapo and other -po genitives

[wm.annis]

As seen in the collab discord, a question on -po form genitives.

Kaltxì ma karyu!

I hope it's all good there. I had several questions about language which I couldn't find help with in any other place, but this one recently came to my mind again. It's whether the genitive form of frapo is frapeyä orfrapoä? And of all other -po pronouns, if to say so. I've heard an opinion that all -po pronouns do the same thing as po, being -peyä in the genitive but I was unable to find any confirmation of this. In my opinion, *frapeyä sounds natural, yet it would be great to know that it is the case, if possible.
All -po pronouns for a quick reference: 'awpo, fìpo, frapo, lapo, tsapo.

All the best,
Tan Jala

Kaltxì, ma Tan Jala!

You're right—all -po pronouns follow the pattern for po itself. So the genitive of frapo is indeed frapeyä.

Eywa ngahu, ma tsmuk.

ta P.

(Quoted with permission.)

[Toliman]

Good to know, thanks for sharing

[Plumps]

I thought we knew this already since 2013 ...

I remember distinctly asking him about that at our Avatar Meet 2013 in Berlin

CORRECTION: It was fko back then, sorry about misremembering 

[Vawmataw]

Irayo ma Tan Jala for asking

IMO, the non-Frommerian rule would be that the genitive of all personal pronouns ends with -eyä, with e replacing the vowel that usually ends the pronoun. However, I'm not sure if it makes sense linguistically and if there are exceptions.