I read through this thread yesterday but didn't respond because the issue at hand was an old post, but here's my opinion.

While fuel percolation is an issue sometimes (and I have noticed with E-brocks in particular that I can hear the fuel boiling when I turn a hot car off, so listen for this) I think the majority of issues are cars with incorrectly set up chokes and incorrect timing.

How often do guys adjust their electric chokes?

In your case, with no spacer, I would start there. You don't need a half inch spacer or anything if you don't want one, but you can buy a thick carb flange gasket (like the factory ones) or stack a few of the thinner ones. However, if by warm you mean the car is 140 degrees you really shouldn't be having percolation issues, but a 195 degree engine with no spacer is going to have issues when turned off.

If it will re-fire within 2 minutes of being shut off but not after 10, then percolation is probably not your issue.