AS a driver I use my 785 to find places "up ahead" that I can stop for required breaks. Garmin taps it's own library for this information. Is there anyway I can get my custom poi files to also show up in this side window?

I am

going out on a limb and say that that is not possible. Maybe someone knows better.
You can set the alert distance for POI's using EPE though.

Nuvi 350 long gone, Nuvi 855LMT, Nuvi 2797LMT, DriveSmart 50 LMT-HD, 3790LMT now my daughters. Using Windows 10. DashCam A108C with GPS.