Nevermind, damned thing STILL drips occasionally.
It took a while to work out that it was happening at all. Until last weekend, I never caught it dripping. I'd just find a few white streaks (what evaporated coolant leaves behind) along the top front surface of the stator side of the engine, exactly where you'd expect drips from the thermostat housing to go.
I've tightened the thermostat housing bolts as much as I dare. I really really really do not want to crack the housing. The bolts have blue thread locker on them so they should stay put.
This is so incredibly frustrating. I don't want to have to top off coolant every month, & feel obligated to take extra coolant along on trips. At this point I've replaced all the cooling system rubber, save for the cylinder head O-rings and water pump area (and I'm not getting any leaks from there).
If I still get drips would it be pointless to place a bead of RTV gasket maker along the bottom seam of the thermostat housing? I suppose that might simply redirect the leaking to the top of the housing, but I'm out of answers at this point.