If I'm too annoying, just let me know. But I still don't know how solve my problem, so I'll try once again.

I would like to use existing Poll package (recently updated by Lukas to work properly in current versions of Pier).

There's POPoll class containing options (as instances of POPollOptions and described by MAToManyRelationDescription) along with other attributes (like deadline, uuid --- unique ID used to identify already voted users, --- etc.). POPolls were supposed to be rendered with special kinds of PRViewComponents using charts but it's a bit off-topic right now.

Voting itself is supported by POVoteCommand class, which is rendered as a form described by MASingleOptionDescription with POPollOptons as options. (I don't fully understand how it works but it obviously does:) By the way, despite unvoted POPoll has POVoteCommand as default, it is still rendered as with View (it's a question for Lukas, maybe?).

So, the main question (still) is: how to join several POPolls in one form providing choices several choices (of different polls) being posted back to server by click on one button.
I tried to do it directly (by surrounding by form with submit button), but I have no information about what was selected by user in callback... And (better) how to do it by means of Magritte?