going back to manual disc brakes from power

the 1&1/32, will displace MORE fluid with the same pedal travel, NOT LESS;
and because of that, will require MORE leg power to get it done.
That's where the booster comes in, assisting your leg.

Because the 15/16th requires more piston stroke, at an easier leg-power, I find the Booster sees less resistance at the beginning of the stroke, and the booster hit is softer.
As the piston nears hydraulic lock-up , it resists the pushrod, which with continued increasing pedal pressure, increases the boost assistance.
Finally, nearing lock-up , pushrod resistance is highest and you are pushing at near max leg power, and the atmospheric valve inside the booster is wide open, which offers maximum assistance.
This is how I have mine set up.
But I have one other variable, engine vacuum. At idle my vacuum is about 10/11 inches. My booster requires ~13 to offer max assistance. If I sit at a light for long enough, idling at 11 with my foot on the brake, on a hill (I have a manual trans) I can feel the assistance start to fade, and it requires more leg power to hold her on the hill.
As soon as the light turns green, and I step on the gas the vacuum goes up, and so, I am ready for the next application.
To mitigate this phenomenon, I re-wired my Line-loc to be a hill-holder. So when I come to that situation again, I just set the lock with the line pressure high enough to hold me there, and take my foot off the brake-pedal. To take off, I give her clutch and simultaneously release the lock as I hear/feel/see the engine bog down. Badaboom!
It took me several tries to get the pushrod length adjusted to where I got the feedback just right. Now it's a dream.

My booster is a big Single diaphragm off a mid seventies F-body.
My M/C is a generic 4-bolter I picked up from the Jobber; I have no idea of the original application. I asked for a 15/16ths and that is what the retired mechanic gave me. It looks like a mid-seventies Mopar.
Good luck.