I do not worry about them ingesting substrate. And normally I do not move them out of their cages to feed. I sometimes move(angrily) overaggressive males out of a group feeding situation. But only at the request of its cagemates. hahahahahahahaha I do have many males that are gentlemen and do not require that.(only with larger species)
Also, you paying has nothing to do with it. And right there is the problem. Whether you paid $32000 for a small group(i have) or its a rescue monitor from the shelter, or its wild in nature, makes no difference. Their abilities are the same. Its some sort of human quirk, the need to mess with the animals. It also seems, the less you actually know about them, the more you want to mess with them. Including PHD monitor experts and other longterm keepers.
In my post above, I hoped to offer a mental picture. That picture was of a naive keeper manipulating a monitor(possible reluctant feeder) The keeper has no "real" idea why he/she is doing, only hoping it helps. That keeper does not understand, that moving that individual monitor(must me already stressed or it would eat your hand off) is only adding more stress and most likely impeding progress. I as an experienced keeper, can only ask, WHY?
I do not think its about ingesting substrate either, I think its an excuse to mess with the poor animal. Inexperienced keepers can come up with any sort of excuse to interfere with their charges. Normally the result is bad and the keeper blames others, again with all sort of made up excuses. Without question, if an animal is in your cage, its your fault. PERIOD
In this, I would think Roybn(not the fault part) is far more experienced then I, for a long period, his job was to take wild caught imports, pick out the nice ones, adapt and adjust them to captivity and sell them as wonderful healthy captives. In that he is an authority and did a great job.
If I have a questionable individual reptile(any stinking kind) I set it up, best as I know how, offer sustinance and leave it the heck alone. I know that does not sound all that experienced, but it is. After its healthy and adjusted, then I can play and mess with them.
The truth is, varanids feed, up to and including on their death bed. They are not like some snakes and do not feed. Oh that is unless your conditions are so far from what they understand.(same reason as snakes) Monitors are just much harder to get to that point.
Of course, there are imports that people pay money(not much) for, that are already dead. But monitors are so tuff, they still appear alive when you bought it. You do understand, that 99% of those farm produced imports are STILL going to die in the first year. I wonder why?
I am not sure about being any sort of authority, I am a reptile keeper, you know, a real one. I do not think there is any denying that. I have kept reptiles for such a long time. As in, I have bred reptiles, of all sorts, each and every year since 1964. I have had varanid eggs in the incubator, continiously without a break since 1991.(I wonder if they will ever hatch, hahahahaha)I am not sure what that makes me, that can be said on this forum anyway, but yes, a reptile keeper. I also do not want to be called a varaphile or monitor guy. As I do not like or agree with many of those types. I do not want to be associated with them in anyway. I treat monitors, as I would any reptile(give them choices) I think Robyn has found out that the approach I and he took with monitors, works really well, in fact, much better with other types. You see, I developed my approach with other types.
With that in mind, I may be an authority on the maintenance of incubators. Cheers