Grafting Question - Root stock buds


5 year old buck +
First year grafter - I have 1o grafts that are starting to bud out, my question is how long should I allow the root stock buds to grow before pinching off?
Rookie here too. I've thinned all of mine to one bud. Once I'm absolutely sure the graft takes then I'll prune off the last one. Not sure when that will be though.

Thank you - I appreciate the help!