So, a day later, this is still intriguing. My own personal thoughts;
-If it's going to be done, people probably want a challenge out of it. Thus, while a number would have to be agreed on by all, I can see a number like 20 being attractve. Why bother doing it unless you're really going to make it a challenge season to season.
-The league to do it in is a league that gets down to 20+ openings (which will happen someday). Move forward with those in the league that we would bring in 20+ owners under these new league rules (or, start the proposed league thread in the Classifieds and see if an existing league that can't fill reaches out).
-Aggressive MWR. The advantage of the bottom now is not just top pick in the draft, but also top pick in the Rule 5 draft, which now means something. Thus, the MWR probably needs to be a little more aggressive, and probably a rotating 2 season MWR (up year, down year cycle)
Now, here's the problems that I could brainstorm
-Compliance. Say the limit of players you could keep on the 40 is 20 players. I don't see a way, from a commissioner standpoint, to easily monitor it. Maybe someone has a view I'm missing
-Timing of designating players. You have 2 full days to do it (the 2 days before the Rule 5, where the players hit the WW but don't clear). You know, every year, there is going to be that guy that was away for 2 days, or forgot, or is stupid. A rule would be needed for that scenario,
-Rule 5 set up fuckups. It'll happen every season. Owner sets his rule 5 player list. owner think "oh ****, I need to change my settings". Owner changes settings. Rule 5 list resets. Owner whines all season. OR owner forgets to change the limit higher than $327K. OR owner forgets to change the numbers of players picked away from 0.