It really depends on how hard it is to obtain comms. For instance right now I can get 2000 fragments, combine them into tokens and turn them in for a TR heart in just a few days if I want to play certain quests exclusively. I do it with my high level toons and past the hearts to the toon that I want to TR. There's zero reason to change that right now. If comms are replacing tokens then then replace them but don't change anything else. BtA for tokens, BtA for comms. The only real change is that every quest should drop comms just like the older quests drop fragments or full tokens. I would be perfectly happy with it still taking 2000 comms for a TR heart if every quest dropped between 40 and 60 comms from the end chest. Or make it even easier, make it 40 comms for a TR heart and make it so that each quest drops 1 comm (maybe 2 on EE) in the end chest.
Also as a few people have mentioned, how much are you talking with your marketing team? Any good marketing manager would be screaming at you guys for possibly causing a drop in spending. Some people are going to be able to TR in a day and some are going to take a year and it's not beneficial to you or us for you to figure out to level that out. It doesn't hurt anyone if someone is able to TR in a day or a year. Once again it seems as if you're trying to solve a problem that's not there.