Woody, I have 2x 15/16ths both of which are sitting in my spares for the future box. I typically change one thing at a time on the car to learn about the difference "that" thing made.
Having done the callipers and discs first, I ran it with the 7/8ths to get the feel for it - the pedal does travel slightly further but frankly not enough to worry me + I find it makes heel to toe action even easier.
There is absolutely no issue with brake performance or feel and I can happily lock the wheels. I no longer have to "stand" on the pedal to do that. And this is why 15/16ths never met the car and quietly sleeping in the "keep safe" box.
The majority of the faff is basically adjusting the length of the rod pushing the cylinder, if you can find an early North South orientation 'M/C (like the silvermine one) and if you can't, then you have to modify your booster to fit an east west one by drilling holes etc, or buy a 280zx booster.
My advice is, do the brakes, see how the pedal feels to you, then decide if you want to change it. You can ALWAYS spend money [emoji6]