re-reading my sudden opinion, this is so much on a mapper perspective hahaha.
this would be a nice feature... if not for the "extreme length maps." sure this would be useful for people finding short maps, such as you. but not everyone likes that. some like full "song-length" maps (5:00). but this would be blocked out be the number of 10 minute to 30 minute maps in the game (ahem ahem to a certain map). the bias is very present (though you yourself probably didn't see at first, it may become apparent once it is actually implemented) and it may result to another surge of ultra-pp-ish-short maps like what happened when ppv2 was released, but on a more modern scale. (since new mappers like attention and that can be nicely done through your proposal of filtering short to long maps).
imo it would be better to alter this suggestion so that song lengths are grouped. there is a list of song lengths on the ranking criteria which dictate what the lowest difficulty should be for a given map drain time. there can be groups of that. in this way, people who appreciate short maps to full song length maps and everyone in between may be satisfied. as for the extremely long maps, its tiring to map so there's less of it, BUT enough to probably deserve its own filter section. bias is also less apparent, and all types of songs are supported.