It looks like this really good and promising mod are abandoned...
So, we need to find a not-so-busy and experienced modder,
who will be maintaining the XenoOps Mod:
> fixing future incompatibilities with newest OpenXcom nightlies
and
> probably fix the existing gameplay-related bugs.
(I cannot do this myself because I'm too busy with real life stuff
like cooking, housekeeping, photography tours and, of course, work).