On an IH forum I'm on, people do quite a few Hydroboost swaps. Some have had problems with T fittings.

Think about this, most, maybe all, OEM applications have separate returns requiring tooling for different reservoirs. If a T was adequate they would do that instead.

Personally I'm not a fan of Hydroboost. Don't care for the pedal feel and Ford systems are awful. You lose power steering assist if you're on the brakes hard.