How many downloaded Logos resources can an iPad with an M chip processor handle?

I wonder if there is a setting so that the iPad would not cut off while downloading updates, if plugged in.

There is not. However, there is potentially a solution for the first part... which is to turn ON "keep display on." I don't know if it would fix any of the potential issues I addressed above, but it is worth a shot. 

However: If you leave your iPad laying around with Logos open, it will kill your battery. 

(I am unlikely to do so... I have "keep display on" turned on so that when I am in a bible study it doesn't keep turning off. But I am good about closing it before putting it away).