@Jarred_Youngblood - I wrote up detailed instructions on my Thingiverse page and the Github repo. Fitting it into the wall box shouldn’t be too much of an issue, but you’d probably want to design your own PCB to house an AC/DC converter for power, and put the DHT sensor up front so it can get proper airflow for measurement.
You definitely can dim the screen, either based on a lux sensor input, or based on time (if you use ESPEasy like I have been doing lately, you can also write time-based rules) or based on an MQTT command from openHAB (based on an Astro sunset event).
That said, for a wall box based controller (with touchscreen), check out this project i found and adapted for openHAB recently (Home Automation Switch Plate) - it’s a fully functional display/controller that fits into a 1-gang wall box, and has a pre-designed PCB for a Wemos D1 and the AC/DC converter. The only thing it’s really missing is a DHT sensor, but you could potentially have a “dumb” sensor hidden somewhere else in the room, and display its temperature/humidity on the HASP (as a bonus, you also get touchscreen control and status display for other openHAB functions).