I don't see anything in either code that prohibits it. P2705.1 of the IECC Residential code (2015) doesn't appear to mention it at all, and the UPC 412 (from 2018 at least) is about Urinals (whether or not a shower constitutes a urinal if you pee in the shower is out of scope of the UPC). :) UPC 408.9 mentions it this way: "Control valves and shower heads should be mounted on the sidewall of shower compartments or otherwise arranged so that the water does not discharge at the entrance of the compartment so that so that the bather can adjust the valves before stepping into the shower spray" So nothing to do specifically with the thing pointed at the door, moreso can you turn on the water without being sprayed by it, which is a good idea anyway since that first blast is likely to be quite cold.

A properly installed glass door will stop and stay with ease. The inward swing is to drip dry youre glass into the shower in most cases.. If you wanna go commando on youre own DIY project you can find adjustable stop wall mount hinges here The latch?? now thats a custom detail !!!

Out of curiosity, if you are trusting the vendor and/or GC to provide and install the actual glass which is the most important component of the system, why wouldn't you trust them to provide the hardware that they found worked best with their glass doors. I did a lot of research when I remodeled but other than specifying the color of the hardware, I left the hinges up to my glass fabricator and installer. I did provide the handle on the glass because that was an aesthetic decision. In my experience, the protection for the glass itself is something that should be researched. After research including asking questions on this forum, I opted for the Showerguard system.

You should match your fixtures and accessories.