If you have something that kind of works for you with the current limitations then all is good.
You're right that my playlist solution isn't practical if you don't want it taking up the screen while you're doing this.
Maybe Steven will read the replies and consider adding some other global hotkeys - besides Delete playing track - that could make it even easier.
That's the first vertical layout of MusicBee I've seen too, though I have no idea what all those numbers mean!
It's surprising to me that not more people use a vertical monitor for something which involves lists, so much wasted space on the average layout. Monitors can be super cheap these days, my vertical full hd hdmi monitor was 20E 2nd hand. Musicbee diserves to be always open on it's own dedicated monitor
Regarding
those numbers, this is my quality control process:
-The first step is checking volume, "Track gain" is the fastest way to see this (Usually shouldn't be above -7db, depending on genre and decade).
-Use a hotkey to launch the track into SPEK to detect quality loss.
(-Also the filesize can show low bitrates, the Mb file size of a 320kbps mp3 should never be below time in minutes x2. Eg: A 3 minute track should never be smaller than 6Mb)
-The last step is listening.
-Once the quality is approved, I insert "(20k)" before the title tag. It's true that not every good quality track has information which reaches 20khz on the spectrogram, so when I confirm the track has been deliberately mixed to 18k I will label it as 20k anyways. When the quality of a track is in doubt or clearly down compressed (and I don't immediately have time to replace the song or it can't be found, which happens usually with older music) then it will get their respective (18k) or (16k) label, which also triggers a
subtle darker highlight.
(This process of comparing tags from multiple files in different folders is one example of where my suggestion for
double file panes would be very efficient.)
For making mix playlists I puzzle with 'BPM" (beats per minute), "Key" and "Comment" (energy level and/or mood tags).