It is a small "flavor" mod to be used in addition to the game option "Alien bleeding". You may have noticed that the said option does not affect the Reapers (because they are regarded as "tanks", I suppose).
So this mod makes the Reaper susceptible to wounds (just as the rest of organic units and as opposed to cybernetic Sectopods and Cyberdiscs), though still more resistant to wounds than other susceptible units (since, accroding to UFOpaedia it has "two 'brains' and two 'hearts' which allow it to function even when heavily wounded"). It receives half the normal amount of wounds, rounded down.
This mod can be used by itself or with another mod of mine, "Wounds proportional to damage" (
https://openxcom.org/forum/index.php/topic,7310.0.html). In the latter case, the Reapers also receive half the usual amount of wounds (which, in case of the said mod, results in 1 wound per 10 HP lost).
Again, thanks to Yankes for his great help.