You can copy/paste each of these via the Import/Export button in Edit Smartlist to create the smartlist.
1. Create a smartlist named: Tracks 5
[Media Type]=[Audio] [Track #]=5 [Disc #]=<2 ~sort=[Album Artist (auto)],[Album],[Track #],[Name]
2. Create a smartlist named: Tracks 1
[Media Type]=[Audio] [Track #]=1 [Disc #]=<2 ~sort=[Album Artist (auto)],[Album],[Track #],[Name]
3. Create a smartlist named: At Least 4 tracks
playlistid==Tracks 5 smartlist,Tracks 1 smartlist ~sort=[Album Artist (auto)],[Album],[Track #],[Name] ~dup=[Album Artist /(auto/)],[Album] ~limit=-1,1,[Album Artist (auto)],[Album]
Where you select Tracks 5 smartlist,Tracks 1 smartlist from the pulldown in the Edit Smartlist dialog.
4. Create a smartlist named: Albums <= 4 Tracks
Playlists is any Tracks 1
Playlists is not any At Least 4 tracks
This builds a list of albums that have a Track 5 (one greater than your request), builds another list of albums from Track 1, and the third list displays only Artist/Album duplicates from the two lists by outputting only 1 of the duplicates.
You may need some tweaks depending up on your circumstances.