I havent played the new Gravity.
But with both Time Manipulation and Beam Rifle, I found I enjoyed the sets a lot more if I stopped worrying about who had the special set buff/debuffs on them and who didn't. They only increase the magnitude of power effects by 20% or so, so using a heal or debuff without first tagging the target isnt a waste.
I just use Temporal Selection as a regen and recharge buff and Time Crawl as a recharge/regen debuff - the extra effects are gravy.
Impact's probably the same. Back when I played a Gravity Controller I'd typically apply Gravity Distortion first anyway to stop my target fighting back and set up containment. So the new Impact mechanism won't really change how you play much.
I admit I have not played Time on a controller (well, I played one to 22, but that barely counts). On corruptors, though, I use Time Crawl to set up the extra mag to hold bosses with Time Stop, and I use it on AVs, and otherwise don't bother. Some controllers don't even take Time Stop, and if they do, they can just stack it with the hold from their primary for bosses, no need to use Time Crawl at all. So, I imagine a controller won't use Time Crawl often. Temporal Selection is quite skippable if you so desire, but if you take it, there's little need to keep track of who has it. If somebody needs healing, you heal them, whether they're Selected or not.
So basically, there's little need to keep track of things for /Time. I won't try to comment on the new Grav, since I haven't played it yet.
The answer is you mostly ignore Temporal Selection.
The Gravity hold is probably in your attack chain anyway so no big confusion there.
I play a Grav/Time and really like it, at least thematically. Here is how I do it.
There is no reason to need to "track" who you have Gravity Distortion on. Anything that benefits from Impact! is single target, so just throw it on a guy before you use Propel/Lift. My ST damage chain is Gravity Distortion-->Propel-->Repeat. You won't be able to run this without a bunch of recharge (and I think even I have something like a .15 second gap at the moment) but Chronoshift helps out with that.
Time Crawl? Don't worry about it. I used it while leveling just for Time Stop's extra mag, but after dropping Time Stop I only toss it out on an uncontrolled boss or an AV. The extra debuffing is rarely worth it, especially in a fast moving team. And I honestly don't notice any difference to my debuffs with or without it.
And I ended up respeccing out of Temporal Selection. Yes, it is a decent buff, and yes, it makes your heals beefy. However, at a 120 base recharge (versus 60 in comparable powers) I didn't feel it was worth it. From a selfish angle, it doesn't help me at all. From a teaming perspective, 25% damage bonus is nothing and 150% regen is totally overshadowed by the fact that the most common conditions for a health bar is either capped or dead, while Temporal Mending has a healing over time component with a fraction of the micromanagement. The recharge is nice but ultimately worth the sacrifice, in my opinion. All together they DO make one nice buff. Just not worth it when I am trying to do my controller thing. And in iTrials? Keeping Temporal Selection on three or four people out of 16/24 feels like a waste of time. (I WOULD take it on a Defender/Corruptor who only has pew pew to do, however.)
Anyway, there is some light on my Grav/Time. The only micro-management you have to worry about in the pairing would be Temporal Selection, and that issue is going to also apply to any controller out there.
I've tried grav in the past for a few levels. The new grav to my understanding makes Lift and Propel do more damage if you have Gravity Distortion on the target.
And then Time (which I haven't played) does more debuff if the target has Time Crawl on it and more buff/healing if the target has Temporal Selection on it.
That means in theory I want to be tracking where 3 powers (including multiple uses) are on various targets so I know which ones to hit.
I imagine it isn't that complicated. You use Temporal Selection on someone and heal/buff everyone and they just get more. And you use area debuffs on foes and just Time Crawl the important ones.
But it seems complicated