redhouse, your idea fails at the point of "if you step into random games"
Any gunboats above 1000

is usually semi-anon at least. There are very few high pot gunboats where it is completely anon, or the multi has enough points on both account to join.
I don't think there's any less chance of a multi in full press, when the phase length is more then 1 day.
Also, the biggest ever game on this site is a gunboat, most of the 7k pot games are gunboats, 50% of the top 20 games are gunboat. Are you serious you want to cancel these and force a lot of players (for examply me) to leave, since I scarcely play full press.
For example, I'm not joining any games under 200

bet size recently, it's a pretty good filter for multis, and I assum there's no multi at all when the bet size is 2000

, I assume you agree. So why would we stop playing those???