I would not presume to misrepresent that I have anywhere near the experience of the earlier posters on this thread with respect to the question that’s been asked, but I do note the different but perhaps analogous debate about lean-of-peak operations. There aren’t too many POHs or erstwhile flight manuals that permit or permitted lean-of-peak operations, yet folks like Mr Deakin have been scathingly critical of that fact. More importantly, they have provided objective evidence in support of LOP ops. Mr Deakin is probably comforted (though he probably didn’t need to be comforted) by the fact that those ‘old’ engines in ‘modern’ FADEC-equipped aircraft automatically and deliberately operate LOP.
I suppose my point is that just because something’s not recommended or included in an aircraft manufacturer’s manual, it does not necessarily follow that it’s not a safe or good idea.
That said, the thing to do is separate the facts from the fiction. For example, the RPM at which generator/s/alternator/s is/are capable of putting out more power than is being consumed by the total load imposed by live aircraft systems, is determined by the laws of physics, not opinion. If the generator/s/alternator/s is/are capable of delivering the required power at idle RPM, the next question is the point at which the voltage regulator switches over – another question of fact, not opinion.
Perhaps the output of the generator/s/alternator/s is very dirty and lumpy at low RPM, even though the load could be borne in theory, thus causing damage to those oh-so-modern GA avionics in practice.