should such questions, at either request of the question asker or the discretion of a moderator, simply migrate questions instead of having them closed?
Surely a mod can do the migration at will, but I doubt they do that lightly or "just because" OP requested it.
As far as I know, a way to justify a migration is for the question to be closed as off-topic for "belonging to other site". This can be done via
Closing > Off-Topic > Migration ...
...which, surprise!, is pretty useless here on TWP as we have no more options for sites to flag as migration targets (that's a status-declined so I won't get my hopes too high). There was also a "more recent" follow-up request asked (about 5 years ago), but no clear actions to be seen for this.
What I see folks do here on TWP is to flag with
Closing > Off-Topic > Other and link on their comment the SE site they consider more appropriate for this case. The OP can then ask for the question to be migrated, or some mod can see this and take proper action.
Now, what I think is not possible (and that doesn't make much sense either) is to attempt to migrate a question that was closed for any other reason:
If a question was company-specific or legal advice I doubt it can be answered elsewhere but maybe here on TWP (but we would probably be guessing) or maybe in Law. This I also doubt as they clearly say that:
Please don't ask questions seeking legal advice on a specific matter. These are off-topic for Law Stack Exchange.
If the question lacked a goal or asked us to make a choice then the question was indeed Workplace related (thus unlikely, if not impossible to fit in other SE site), but off-topic. Hence no migration.
If it was unclear what the poster was asking then definitely it's a lost case and no migration required (at least not until it is clarified).
If the question was too broad or primarily opinion-based it was again Workplace material (no other place to migrate) but is not answerable in a clear and objective way, or as specified by the Guidelines for Great Subjective Questions
So, bottom line, I think that what you ask is already actively carried out by our kind and diligent Moderators ... and with some of our help :).
They currently handle the migrations that take place in TWP, either by their own judgment, OP's justified request, or well with the outputs from the organic Closing Process handled by the Community.
This you have probably seen by now, when we get questions that go to IPS (which seems to be our main migration target) ... did I hear we should add that as migration option?... oh wait, I already explained that part.
Still, I would like to hear what our Mods have to say about this question and my perception of it.