Is it safe to undergo subcision every week?

I have never heard of this frequency. For acne scars, microneedling, Infini, PRP and Bellafill are my recommendations. If your doctor has experience using this protocol, then go with it.

No, it is not recommended to have subcision every week.  We usually recommend subcision every 2 months, and  at the earliest every 6 weeks.   The reason for which you wouldn't want to repeat subcision too soon is because you want to allow the normal healing cycle to occur which produces new collagen and so that the tissue is soft again.  If you repeat it right away, the tissue will be indurated or hard and still healing.  Red scars should also undergo Vbeam or Pulsed Dye Laser (PDL).  PDL can be performed at 2-4 week intervals between treatment sessions.