Mine is Fuse all the way, and I have had no stretch at all. None. Nadda. Zip. Zero. I shoot a peep w/out an aligner and it has NEVER failed to open properly. IMO, the Fuse string is right there with the best. There are some minor differences, but nothing radical.

Wait until the weather gets warmer. That is when you seperate the good strings from the bad. The heat will cause a less stable string to creep.

I am a die hard Hoyt fan, and absoloutely love the Tec design bows, I own 4 of them currently, however every single one has been unable to maintain peep alignment with the factory string.
While yours has not moved yet, I assure you that it will eventually move. For me, I found that out the hard way, sitting in a stand hog hunting in the Texas heat. I drew back and my peep had rotated 90 degrees. I couldn't see and didn't take the shot. The peep had been in perfect alignment until that afternoon.

I will admit the Fuse strings are better than the original Hoyt strins, they are no where near the quality where I would feel comfortable shooting a peep without an aligner.