I started shooting 9 major shortly after uspsa allowed it, probably close to 10 years ago. There was no data for this so I stumbled through it on my own, finding out what works and more importantly what did not work.
What i I came up with was a oal if 1.170 with a Montana Gold 124 and 121 bullet. I use HS6 or Silhouette powder. Yes other powder will work but I have found no need to try others.
Yes you can load load longer to get closer to 38 super length but you are only kidding yourself if you think that will make the 9mm perform like a 38 super. It is still a 9mm with powder that will work in the shorter case. I actually have loaded out to 1.20 but I found no real reason to do so and yes you will have problems with loads that long. Maybe not often but usually at the worst time. I much prefer the reliability to any small advantage, real or perceived, gained by loading that long.
So so yes you can try to reinvent the wheel or just ride on a round one like everyone else. ?