(removes moderator hat)
The following is an un-nuanced and declarative answer. I acknowledge that there is room for discussion here, but I think that it is worthwhile to have a general policy which is clear. Edge cases can be handled as they arise.
Is it acceptable to post an answer that has a chance of being incorrect?
Answers on Math SE should be authoritative. If an author is not certain of the correctness of their answer, they should not answer.
A potential answerer who is seeking feedback on an answer is invited and encouraged to engage with other users in chat. The Mathematics chatroom is a good place to start with mathematical inquires. One might also ask for help in the Constructive Feedback chatroom, though this room is generally used for requesting feedback on existing questions and answers, and (per a recent change in the room topic) focuses mostly on the technical aspects of posting on Math SE (as opposed to the mathematical merits of a question or answer).
(puts moderator hat back on)