Hey there 
I would like to propose a nightbot setting where the streamer is able to set the maximum amount of minutes a song/video lengh can be when adding songs to their playlist (either themselves or requested by viewers).
1) On one side, occasionally there are songs, that are longer than 10 minutes and currently those can’t be added at all - not even by the streamer themselves into their own playlist.
Here is some example music I encountered this issue with before:
2) On the other side, with requests close to 10 minutes possible, if you for example allow each viewer up to 2 requests then 3 viewers are already enough to clog a request queue for a whole hour.
It would be understandable if some streamers would like to lower the maximum minutes to something like 5-6 minutes, so more viewers have a chance to request a variety of different songs.
So yeah, I think being able to set a custom maximum video lengh would make Nightbot better adjust to each streamers specific preferences and needs.
Also I think a streamer should always have the most amount of control over their setup and such should always be allowed to add videos to their playlist regardless of limits.