How likely is a patch for this to get accepted?

In June 2021 Nick Clark proposed an RFC process to answer that very question. The proposal was adopted, and the documents have since been renamed to PPCs ("Perl proposed changes"). A description of the process is on github, and in that repository you can see existing PPCs along with any discussion and resolution.

My initial reaction is that this would be better as a module than as a core feature, certainly for initial acceptance and usability testing.