Will fat graft on face make my rosacea blood vessel worse?

There should be no correlation between the two.
Facial fat grafting is tricky business and I recommend patients stick with fillers.
Fillers are precise, predictable and forgiving. Grafting fat is the opposite.
If you going to stay with fat then make sure your provider has to experience and skill to deliver these results with quality on a consistent basis.
Do that by having in person consultations at which time you should ask each provider to show their entire collection I’ll before and after pictures which hopefully will include at least 50 sets of before and after pictures that we’re taken at least three months from the date of the procedure.
Seeing a handful of preselected pictures is not sufficient to confirm someone has mastered this quite tricky procedure.
Best,
Mats Hagstrom MD