It's not a matter of length of veg vs yield.
Yield will be the outcome of plant canopy and your skill. The height of the canopy when you flip to flower will be dependent on the stretch you expect for the strain. You need to leave enough space between the top of the canopy in veg and the lights to account for growth in flower.
The time in veg to get a good, even, canopy is dependent on the number of plants and how good a grower you are. You can fill a 4x4 with one plant or 10, but the fewer plants, the longer you will be in veg to fill the space.
So nobody can answer your question.....