I think you might be approaching this too analytically.
I can't fault you on that because I did the same thing when I got started reloading.
Turns out that your analysis might be exactly correct until you put your particular rifle barrel, trigger, and stock into the equation.
I shot factory loads in my new CZ 550 in .30-06 and noticed that it didn't like 150 grain grain ammo as much as 165-168. It didn't seem to like 180 grain as much either. It shot just about at 1 MOA with factory ammo.
Then I started to reload for it and tried 150 and 168 grain SMKs without much improvement using factory velocities and normal depth seating.
When I switched to 175 SMKs the rifle came into its own, especially when I experimented with velocity and depth. When I found the right velocity and depth combination for each weight bullet, I managed to get it to shoot several loads under 0.7 inches with 150s, 168s, and 180s and about 8 different loads to shoot under 0.7 with 175s. One particular 175 SMK load shoots under 0.6 inches at 100 yards.
I found that velocity and seating depth made the most difference and that none of the factory ammos matched the velocity or depth that made my particular rifle preform best.
I also agree on the bench press over the hand press.
Get the best bench press you can afford because you will be use it a lot.
I have loaded just about 9000 rounds of center fire for 5 calibers in the last 18 months.
I can't imagine doing that it with a hand press.