Yes studies have shown that an increase in testosterone will result in heigth increasement. How big this increase is hard to say, but i would not thing its the big deal. Question is does it accelerate the growth, or does it make it go above our biologic max.
Reason that some say steroids stops growth places is due to estrogene, estrogene has big role in stopping growth plates. Increase estrogene and ure growth places will decrease or stop.. Ive read also seen a studie saying anavar could, this makes great sence since anavar does not aromatise into estrogene
Leaveing compounds like primo - win - var useable for this little advantage.
This is what ive gathered over some years of reading on this subject