Depends on a T and how much he knows you- having a plan is generally recognised as a warning sign, however, I have my perfect plan since I was in my late teens- so for around 10 years now. My T knows this (told him after 3-4 years of therapy, no details, just that I don't need to plan SUI anymore) and understands that it doesn't mean that I am unsafe (it actually keeps me more safe and sane and gives me the strength to go on- like I'm OK cause I have my plan, if anything goes wrong I can use it so why not try this? There's nothing to be afraid of... - it's not for everybody but it works for me).
Anyway, if you just came up with this plan it might be a different case- you're saying you're safe (really happy to hear that). Definitely start with that and then if you feel the need to share the plan with your T just go on. SUI thoughts need to be talk about- the sooner the better.