I'd say: we have the tools to make this statement explicit. Up-vote the question and leave a comment saying that you up-voted because it's a good question, but you think it is not on topic for reason X.
If it needs to be migrated, that is probably the end of it. If it has a different problem (e.g., being opinion-based), then you might also consider ...
It is your vote and you should vote as you see fit. I think of up votes as saying this is a good question that is a good fit for our community. I only like rewarding people for doing things that help our community. There is also a small reduction of work if closed questions are not up voted since closed questions with negative vote totals are automatically ...
Or would such unethical accumulation be detected by the system and intimate the higher moderators?
Yes. This is vote fraud, and moderators have tools that alert us to this.
In some cases, these votes may even be reversed automatically without moderator intervention, as described here.
(The specific nature of these tools is kept private to avoid people ...
From the help center:
As the author of the question, you have an additional option:
accepting an answer that you believe is the best solution to your
To accept an answer:
Choose one answer that you believe is the best solution to your
To mark an answer as accepted, click on the check mark beside
the answer to ...