Have you read all of the linked articles from the "Injuries : Fingers - Links" section of the UKB Wiki?
I just posted a question on the Phsio Q&A thread regarding the A1 pulley asking the same question. I'm now three weeks out and should be looking to start climbing on it again, so it should be time. From a basic physics perspective, I would guess that open handing small holds is probably less impact on the A1, but large full hand or even full finger length slopers are likely to be rough on itas they engage that pulley.
How sure are you that it's an A1? If open handed climbing is causing issue it may be a lumbrical (the long tendon connecting fingers and forearm muscles). The treatment is the same but I'd avoid climbing if its causing discomfort.
I assumed it was a tear but then got shown how to do proper finger/wrist stretches and started regularly doing them before and after climbing, and after the second session the tenderness had *completely* disappeared