I think a clarification of the ReCo 10 guideline: "Eliminate the penalties of Fatigue and wounds" (ArM5 p.134) might be needed, as there are some obvious disagreements on its meaning.
The most crucial one is whether Unconsciousness, Incapacitation and Death count as "penalties" in this sense. Endurance of the Berserkers (ArM5 p.134) suggests Unconsciousness does not; The Tireless Flight (HoH:TL p.102) may be read as suggesting otherwise. Both are silent on Incapacitation and Death. As I see it, it would be highly unbalancing to allow the guideline to prevent Unconsciousness and Incapacitation/Death.
A secondary issue is what "Eliminate" means in the context of the guideline; in particular what happens when the effect ends. From Endurance of the Berserkers, it seems that the penalties return in full at that time, and this is how almost everyone ends up playing it. If so, I think "suppress" would be a much clearer term for the newcomer to the game.
Thus, I think the guideline should be clarified as:
Suppress all penalties from fatigue and wounds, short of Unconsciousness/Incapacitation.
Third, by either wording, it seems very clear to me that a character under the effect for a prolonged period still recovers fatigue/heals wounds. I've seen a few troupes that assume otherwise, mostly by analogy with healing spells that suppress "natural" healing for their duration. I am not sure how the wording could be concisely improved in this regard. Perhaps adding:
A person under this effect still recovers fatigue and heals wounds normally.
To be fair, having the effect suppress natural healing and fatigue recovery might be indeed the best solution: even with this limitation it is a very useful, potent effect - without, it may be unbalancing. Then a clarification is certainly needed. Perhaps, instead of the above, something like:
A person under this effect does not naturally heal or recover fatigue.
Fourth, related to the guideline,but much broader in scope (so much that it may not be worth addressing, but I think it's definitely worth considering) is what happens when a character "overspends" fatigue levels past Unconsciousness - which can happen in several situations, from casting Rituals, to using Life Linked Spontaneous magic, from Scuffles to strenous exertion. Most (but not all) situations do provide a rule for accounting for overspent levels, but it seems different in every case. While this does not necessarily need a fix, I think a unified rule could make the game simpler and more consistent.