I think the whole framing was that the reason the problem space is hard, is that if you deliver too much at once, your body notices and treats it much like if it found splinters stuck in you - invasion of foreign mass to trigger inflammatory response.
I am not sure if the burning was related to inflammation. I recall the sensation of marker fluid aburning as it moves towards the heart, but it might just be a sensation rather than a reaction. Wasn't clear from the post at least.
Maybe one could burst only some convenient nutrition that is easier to deliver in higher doses like glucose, while still drip-feeding the bulkier macronutrients.
Another crazy idea could be to intentionally introduce glucagon and insulin to artificially induce highs and lows.
I'm sure it's a very hard problem space, but it might be one looking for a creative patient willing to put effort into further research...
The explicit quote from the article was "believing it required so much liquid, and such a high concentration of chemical nutrients, that it would cause inflammation and burning when administered.", and I am assuming that the former was not just redundant with the latter.
Directly mucking with glucagon and insulin for anything short of directly demonstrable life and death is going to be a fraught proposal in almost any circumstance, I would speculate, given that the risk is not just wasting away from malnutrition but much more direct tissue damage and death. (Much like I suspect something with a risk profile like Accutane's would not get approved again _now_ with the body of evidence we have for what happens if you introduce something that's "almost, but not quite, vitamin A" into rapidly growing bodies...)
That was the quote describing why they originally thought that intravenous feeding was entirely impossible, which proved false, so I didn't take it as an observation regarding solution as it was later invented.
It was how the original solution was invented and tested, with resistance to mucking about likely limiting it's development significantly.
It is certainly not a game to entertain without understanding the signficant risks, but healthy people can intentionally take on extreme risks, so I see no reason to stop a patient with a coordinated plan for research into bettering theirs and others situation.
