I wonder if you could do something like play a 58 game season. Everyone plays everyone twice. At that point you take the top 20 teams and play a round robin, 19 game finish. That’s 78 games.
The bottom 10 get relegated and play in a development league to finish the season.
The other option is to just stop tying draft picks to record. The incentive to tank is to get a high pick. If it doesn’t guarantee it, teams will keep playing.