Y'know, gaining Convert kinda reminds me of when I first leveled the job, trying to figure out the optimal balance of Strategems/Sublimation/etc. All I've determined so far is that it's going to vary widely based two major factors:
-Sublimation setup: Merits, AF/Relic, HP/Race all play a role in how fast your average Sublimation charges, so this varies a lot by player. I have both AF/Relic and full merits and my charge usually maxes in 5-6 minutes while actively casting; or it can happen a lot faster if I don't cast at all. Even assuming your gearswaps are completely optimized, there's always going to be a minimum charge time, and your real charge time which is going to vary a lot based on your actions.
-Strategem usage: If you just spam Parsimony every time a charge refreshes, you could probably get a good rhythm going, but that's hardly optimal. Personally, even if I'm using charges on nothing but Parsimony, I only use it under the following conditions:
-@4 charges, or will be before next nuke (30s~ usually),
-MP is within Uggalepih activation range,
-Sublimation/Convert are down and MP is low,
When you consider all this, it becomes very difficult to come up with some ideal strategy that applies to more than a very particular set of circumstances; there's just too many permutations. Honestly, I think trying to perfectly balance Sublimation and Convert so that Convert doesn't interrupt Sublimation is pretty much a fool's errand, as sitting around on recast timers for either is making you much more inefficient than the alternative.
This is how I usually start off:
-Parsimony first nuke to get recasts started
-Free nuke until MP is within Uggalepih range, then start spamming Parsimony
-Use Sublimation once your MP is low enough to stay within Uggalepih range and continue nuking to low MP
-Convert, Cure, Activate Sublimation
At this point my timers are all over the place, so I just make the best decisions I can as timers diverge. All I know is, Sublimation is a gradual effect on a very low recast, while Convert is an instant MP refill on a long recast; Convert always takes priority. If Sublimation gets cut off below 150ish MP by Convert, I'll usually nuke once and use it to get the cycle going again. My focus is always on keeping recasts rolling as much as possible on things like Strategems and Convert to maximize their benefit, and keeping Sublimation active as often as possible. I would certainly never wait an extra minute, or even an extra second, on Convert just to see that shiny 'Sublimation: Full' icon.