Bulk Proof Basics - when is "ready"?

Right now I am testing some 1-step (no preferment) recipes at room temperature and I wonder how I know when the time is right?

I tried a baguette type white dough. Let it proof for about 8 hours and it increased in volume. But I have no idea if it was too soon or too late. I am aware that temperature, amount of starter and time play a role.

I let my starter (a stiff 50% starter) raises about 100% when I feed it. Bread is about 60% hydration. In the dough I add about 15% starter.

Is there is percentage in volume increase that tells me "time to start"?

I would then do some type of video recording find the sweet spot.