[Samhain]

Besides inferring from lack of activity (which is darn tough with score graphs off), the only way I know of is to remain on the screen that shows all of the banners of the nations in play. Any X'd out when the hosting clock runs out likely staled. I know from administrating a past game (though on llamaserver) that many players though will often get their turn in just minutes before the game hosts.

I've suspected that at least in some cses this is actually a form of metagaming, acting as if you are going to stale to get your opponent to take a risky move. I've considered doing it myself but have been too paranoid that either a internet connection failure or real-life event will cause an actual stale. So, I tend to do the opposite, get a draft turn in as soon as I can and, if possible, a more considered turn later.