Here I am again, after a considerable break, trying to take some rest (ngal gso). Constant and cumbersome administrative work can, need not necessarily, be a cause for weariness or exhaustion (ngal ba). If it goes on without a ngal gso—by the way why also ngal bso?—it might take the form of a kind of suffering (pain or discontent) (sdug bsngal). Hell (dmyal ba), as we all know, is nothing but an existence characterised by extensive and intensive suffering (sdug bsngal).
The point I am trying to make is if Tibetan words ngal, bsngal, and dmyal are linguistic-historically cognates. I have not tried to find out if someone, somewhere, sometime, has already discussed this. Apologies if this thought is nothing new. To me at least it is. If someone has had already this idea, then consider that also someone else, too, has a similar idea. If no one has thought about it so far, consider this a seed for speculation.
Life is serious enough. So cheers! :-)