Maybe you’re right on that. Since Lexicon DJ gives the option to convert smartlists to playlists, I use it not knowing. The reason I switched to Lexicon DJ is because I had a complete meltdown of Engine DJ syncing to Engine OS. That is described here: Vanishing Playlists. Many of the smartlists disappeared in the sync panel and would not sync.
Lexicon DJ solved the problem, but I do sacrifice using stems (which I didn’t use, but might if they improve). To keep things simpler, I prepare in Lexicon DJ even though I like the Engine Desktop interface better. I do get the benefit of easily syncing to other DJ software.