If you're willing to install fb2k v2 in portable mode, you can test this console spamming album total build I made (32bit only). You can play the tracks with the biggest discrepancies you get with enhanced playcount to see what last.fm says??
Ok I installed the version of the plugin you linked (in the foo_enhanced_playback thread). The console stats look accurate as far as I can tell. The only thing throwing some of them off is the arbitrary use the ` and ' character in track titles (which on my end get changed by foo_musicbrainz). Here's an example.
Raw Last.fm playback stats in CSV where artist is Coldplay and track is Don['’|t Panic.
Artist, Album, Track title, Play count, First played, Last played
Coldplay,, Don't Panic, 20, 1/24/2006 7:02:00 PM, 11/6/2013 7:43:00 AM
Coldplay, Blue Room, Don't Panic, 31, 8/24/2006 7:36:00 AM, 8/11/2014 3:53:00 PM
Coldplay, Blue Room, Don’t Panic, 6, 2/25/2018 9:02:00 AM, 4/28/2022 3:17:00 PM
Coldplay, Garden State, Don't Panic, 20, 1/24/2006 7:02:00 PM, 11/6/2013 7:43:00 AM
Coldplay, Garden State: Music from the Motion Picture, Don’t Panic, 1, 2/25/2018 9:09:00 AM, 2/25/2018 9:09:00 AM
Coldplay, Parachutes, Don't Panic, 40, 8/24/2006 7:52:00 AM, 9/8/2013 9:39:00 PM
Coldplay, Parachutes, Don’t Panic, 3, 2/25/2018 9:08:00 AM, 4/28/2022 3:32:00 PM
Overall total for Don’t Panic is 10.
Overall total for Don't Panic is 133.
I changed the title from Don’t Panic to Don't Panic and these are the results from foo_lastfm_playcount_sync in the console:
Overall total for 'Don’t Panic' by 'Coldplay': 10
Garden State: Music from the Motion Picture - 1
Parachutes - 3
The Blue Room E.P. - 6
Overall total for 'Don't Panic' by 'Coldplay': 133
<album missing> - 42
Blue Room - 31
Garden State - 20
Parachutes - 40
I guess there's a sweet spot here for how specific the matches should be by not matching for punctuation maybe? Though it's not really your problem. It should be Last.fm doing the aliasing but they don't seem to care. I'll probably switch to ListenBrainz when my fav apps have plugins for it.