Milliseconds have no purpose for RTA, people who submit with it are usually submitting an incorrect time, it is only useful for IGT since the game accurately displays clear times. With IGT, it's good as an optional timing method, eventually when people start getting ties with RTA, IGT can determine who is faster to break ties. It is also not good as a main timing method simply because there's more to just adding IGT, you have to calculate each stage, add them up, etc. We want to be speedrunner friendly, RTA is the way to go with IGT remaining optional.
I know this thread is 1 year old but I have a question about that. You say that people who submit with ms are usually submitting an incorrect time. But what if I verified myself the exact time with a editing software? It is not possible to add it? I guess because you don't know who verified it and who didn't? And I guess it will be too tedious for you to verified every run to see ms?
Alright and what about ties? We can't verified milliseconds for RTA to break them? To see who really has the WR?