I would guess that a lot comes down to the IDC that you choose as well as the type of instructor you want to be. If the IDC pushes you in the direction of all skills being taught kneeling, guess what you are likely to end up doing. If they teach all skills neutral, you will end up with a lot of better instructors.
I talked with a PADI instructor examiner about this. He said that the really big IDC centers guarantee that their people will pass the IE by having them do a very carefully choreographed routine for each skill they have to demonstrate. He said that the choreographed routine includes any step they think any examiner will want to see in the skill, meaning that the demonstrations are unnecessarily long and complicated. They practice them over and over and over and over until they do it perfectly. He said that if you put all the instructor candidates from one of those centers in the pool together and gave then the signal to perform a skill, it would look like a synchronized swimming routine. These skills are almost invariably done overweighted and kneeling, because there will be no tendency to float at all, which would disrupt the perfection of the routine. He said he personally hates to see it done that way, but under current standards, there are no rules against it, and the students get top scores.
The Director of Instruction for a local dive shop came from one of those programs, and he made following those procedures (he had videos) mandatory for DM training, even though the DM graduates would be assisting instructors who will invariably teach the skills differently. Ironically, he had learned about neutral buoyancy instruction after getting that training, agreed that it produced far better graduates, and did it himself while he was instructing. That means that he was teaching DMs to do a skill in a way he himself believed to be inferior, and the graduates he had just taught to teach that way might then assist him in a class and see him doing it completely differently. He had no problems with that. He said that once people learn to teach the skills the way he had been taught, they were free to do it another way in the real world.
That did not make any sense to me personally, but who am I to argue?
BTW, PADI is currently redesigning the IE, and I was assured that buoyancy instruction would be emphasized.