Either one works; they both have pros and cons. A single file is easier to deal with but Google is correct, due to the way ID3 tags work. Listeners would just see a generic "[your show name] with DJ [you] on Radio Lemmy" for the entire show.
With individual tracks, listeners would be able to see the song title of every track, but I can't guarantee that every tune will play in your intended order. You would get your own programming block for the hour, where your songs would play on shuffle, with bumpers playing every few tunes. I could manually program the song order, but TBH if I had to do that for every single show it would get tiring quick.
So if you want a specific play order, it would be easiest to send a single file. But honestly I'll take either. The most important part is having content to play on air, regardless of how I get it.
Seems to me that you got an early or cheaper HDR display, then. To me the difference is night and day.
FWIW, HDR does its best work if you have a display that can do true blacks. If you don't have an OLED, mini LED, or full array, you're going to have a hard time noticing the difference, especially if you don't know what you're looking for. HDR works best in either extremely dark or bright scenes, so having a display with a near infinite contrast ratio is important.
Here's a hint for any display: Look at some HDR clouds while you toggle HDR on and off. You'll definitely notice the difference there. Also check the teals. It's less obvious but SDR displays can't do a proper teal.