Some of xerxes' finest modules, indeed. Quite a few of them were the result of #mod_shrine One Hour Compos, if I recall correctly (I'm pretty sure I hosted the compo for "xerxes-24-lovely.it" as I recognize the sample pack as one of those that I made :) ). The exe is completely safe to run.
QuoteIt also taught me that there are .it modules made with openmpt that can use a different mixing scheme than the older compatible mixing setup that impulse tracker used. I didn't even know that was a thing until I heard that it played differently in schism tracker than in audacious (which has an openmpt core to playback modules). Pretty interesting.
The different mix mode being used (MPT 1.16) should only affect volume levels; notoriously ModPlug Tracker had a user-configurable pre-amp setting that was not stored in modules, so depending on the user's setup, modules had a different volume depending on which computer they were played on. The "compatible" mix mode fixes this by fixing the pre-amp at the same value as Schism Tracker, which also happens to be louder that ModPlug's old default.
Apart from the mix mode, those files were of course made with ModPlug Tracker 1.16 and may exploit a few ModPlug bugs here and there, of which OpenMPT will emulate many (as it can correctly determine that the files were saved with MPT 1.16), but other software not based on libopenmpt will typically not handle those bugs. XMPlay / BASS can handle a handful of the most obvious playback bugs found in MPT.