Here is the reason why it's not safe to repair seat belts.
It is not safe only if you do it by yourself or give it to someone who doesn't have experience and knowledge about this subject.
You may think, it's not that hard, it just needs to roll, right?
Well, simple answer is NO! The mechanism of the seat belt is really complicated, and it has plenty of small parts inside, and they are all really, really important.
But there is a way to make it right and we know exactly how. Basically, we rebuild those seat belts, replacing all the broken parts and igniters, using only OEM parts, to make repaired seat belts work and look like new. Seat belt repaired the right way by professionals will definitely work.
To summarize, it is safe to repair seat belts on any car make and model, but it needs to be done the proper way with proper parts.