look at the amount of metal look at the forces involed. teh weld isn't going to be getting much greif and very very very unlikey to fail in a catostrophic manner. alloy wheel fails due to strain and fatigue are nearly allways spoke related, if welding centers in to a rim much more thought and testing would be done, fails of the actual rim itself are inpact related.
also wheels give you a hell of a warning if they have damage to the rim itslef, they go FLAT
