One, is that it seems you are assuming "1 zone" is equal to 1 stop, that is not true. In classic zone system thought, zones are properly described by the characteristics that they will have in a print, like "shadow with detail", not a specific luminance measurement. Again in classic ZS thought a scene luminance/brightness range may be 7 stops or 14, either way there are always 11 zones.
Two, you seem to be expecting the paper to have the ability to display an 11 stop range, it can't and PS can't fix that. About 7 stops real luminance is the absolute limit of what a high gloss paper with ultra dark blacks can show. Use matte paper, as you did and you may only get 6, maybe less.
All 11 zones can fit on the paper but the paper displays them in roughly 1/2 stop steps. (This is an over simplification but think 6/11.)
The other question that pops into my head is "how will you be printing?"
I ask because plus and minus development are only significant/important when a specific paper grade is the target.
If you are using VC paper or digital methods to print, plus and minus film development has a reduced value and can actually be a detriment. With your 35mm roll film, if you are like most of us, typically subject matter and lighting situations will be mixed on a given roll, when that's true adjusting development for one situation on the roll messes with all the others.