Dom 1.5XT-R ball bearing for stock internals, spool by 3300 and breathes like a 20xt, amazing turbo Dom 3 for forged internals.
340 on stock injectors, so running premium? Seems like a stretch. What dyno is that taken on I 'was' running the vf52 at 21lbs on e85 (30deg timing up top) and seeing about 326 on mustang, thats with 1000cc injectors and a 255 with almost full stage 4 mods, and thats HOURS of tuning work.
I went to a TD-06 20g for a stint, and couldn't stand the lag. The 1.5XT-R flows better and spools almost like the VF-52.
Problem I see with your injector logic is that you can do all those mod's but it's not necessarily to "make your motor and turbo work less", it's "SO, you can make your motor and turbo work harder efficiently" The bottom line is more power requires more gas/air, even if you do a TGV delete, that simply allows you to get more Air which implies more air fuel into the motor at the same required boost, which would require more fuel. The lightweight crank, I would agree gets you more power to the wheels, but not 30 more than what others claim on a premium tune with stock injectors. EL Headers might net you a few hp with similar air fuel by "letting it breathe" but again, this is more about supporting more air fuel, again requiring more fuel. Not trying to flame, but I wanted to try to understand what you are saying, as I feel it may point people in the wrong direction.
Bottom line, if you are going to run a big turbo, you are probably going to run meth/E85 with "HAS" to have bigger injectors, you will smoke your motor from leaning out up top if you don't.
Out of the three choices you list, I would run the VF52, it is a very nice turbo for a stock motor. The spool vs flow is pretty hard to beat in a 2.5, the Dom 1.5 X-TR is 1600 by itself, you can get away with a stage 2 tune on the VF52 on stock injectors, they will be working though. Realistically expect about 290-310 on a Mustang dyno on a premium (no meth) tune.