They are exported so you can sync to a Denon device, where they do work. Not syncing them means you could lose them and that’s probably not what you want.
Yeah that is a better way. It’s silly Engine desktop doesn’t support streaming tracks yet, that would solve it. I’m sure they will support it at some point.
Not exporting streaming tracks to Engine desktop would cause the problem that your playlists would become inaccurate (normal tracks synced, streaming tracks skipped). If you then re-import that playlist, streaming tracks would be gone from Lexicon too.
Lexicon to everywhere else (Engine and Rekordbox in my case)
I dont think i have ever had to sync back from Engine/Rekordbox to Lexicon.
i have created a smart crate in lexicon of to capture all the streaming tracks which i do delete before syncing to Engine DJ.
In terms of maintaining playlist integrity, are you referring to playlists that have both streaming files and local files. Serato does not have this feature. Engine DJ officially does not have this feature as well but its possible to combine streaming and local.
A check box in the export settings to exclude streaming tracks will be clutch i think.