I finally got around to a tally… about 200 smartlists in Lexicon DJ. There were probably around 100 when Engine DJ stopped syncing correctly. But, if you read various threads here, it may be syncing all sorts of playlists can become problematic, out-of-the-blue, with Engine DJ.
I’m still converting playlists to smartlists. But, for the most part I can just drop a properly tagged track in the collection and it falls into many of the appropriate smartlists. The exception is the Sets category of playlists.