There is a question I believe to be well on topic, relevant, and interesting. It is asking to consider a fictional scenario and evaluate, as given in the fictional scenario, whether it is possible to achieve with classical physics.
It is, I believe, people who are misapplying the prohibition against fictional physics, who have voted to put the question on hold. The prohibition is:
Questions about fictional physics "Could a warp drive get you out of a black hole?" Questions about physics of fictional worlds which are not sufficiently grounded in real physics are off topic here, but they may be on topic at Science Fiction & Fantasy.
This seems to me to suggest the prohibition is against trying to determine whether fictional physics rules would allow something to happen.
Is asking for a scenario to be evaluated against real-world physics then off topic? Is it off topic to ask if a fictional scenario is possible as it is described, if the physical rules being asked to judge it against are real-world rules?
Example, would asking if Verne's moon cannon is possible be off topic?
Is there recourse if off-topic rules are misapplied?