I just asked a question on Stack Overflow, and then ended up migrating it to a Stack Exchange site other than the ones in trilogy. But now I can't say "belongs on miscellaneous non-trilogy stackexchange site" when voting to close. What should I do?
On all non-Meta sites in the network, you can now vote to migrate to any one of (up to) 5 predefined target sites, one of which is always the per-site Meta.
If none of the available target sites are suitable, you can still close as simply "off topic."
Diamond moderators can migrate a question to any site in the network (flag for moderator attention and state your case).
The predefined migration paths are SE staff controlled, but if a community can make a convincing argument to add/remove sites from the list, the list can be changed.
Probably best to simply close as
Off Topic for now.