I can't offer an alternative, but given that you used MoinMoin for years, you could also look into porting MoinMoin to python 3? Most likely you will learn enough about its codebase to add the features you wanted in 2018.
If the upstream project is dying, you might not only do yourself but others a favor by reviving its codebase.
If the upstream project is dying, you might not only do yourself but others a favor by reviving its codebase.