OP you're asking for a personal optimum that is difficult to answer based on generalities. You're golden number could be anywhere between 150mg and 400mg.
One approach could be to start at say 200mg, and increase by maybe 50mg each subsequent week til you hit sides. But even that's not perfect. But it's doable. It'll require patience, careful self-scrutiny/awareness, and the acceptance you could overshoot.
But...if you've got primo in the mix from the get go then you won't get a true max test-only weekly dose that you can tolerate without an AI. Primo in this respect is VERY unpredictable. First, it might not be primo. Second, some guys finds it somehow "reduces E2", to varying degrees. The exact mechanism, fuk knows. But having Primo (or masteron) in the mix can change things. However, some guys find it has no impact on E2. Hence the unpredictability when it comes to individual experiences.
It's gonna be trial and error (or lucky fluke guessing), unfortunately.
If I were you, with the gyno, I'd be tempted to use masteron instead of primo.