Out the overflow tube is no biggie. Don't worry about it. That's why the tube is there. In my experience, temperature swings while parked can cause a drip.
If it becomes excessive, then you probably need to overhaul the waterpump.
FWIW: Mine did that for a while after rebuilding the waterpump and then stopped. I haven't seen a drip in several years.
That was going to be my suggestion, but as you say - sometimes the overflow will drip a little for no obvious reason. It's only if it's all the time that you need to think about a water pump rebuild, IMO.
To the OP: Is it possible the new hoses you installed are not oriented properly?
No. Suzi did us a solid here - it's almost impossible to install them wrong.
They have a bend to them and different diameters at each end. It is also possible the O-rings on the unions are not seated correctly. Or, as you suspect, the thermostat could be your source. I haven't dug into the thermostat, but did the hoses and unions last year.
O-rings (#9 in the Radiator Hose parts fiche) are original AFAIK
. I have new ones, but decided not to attempt replacement when I put on new connector hoses. Too much work, and the leak wasn't coming from there anyway. Well enough alone and all that.
Haven't had any more leaks from those hoses or their fittings, so I suppose that was a good call.
Reason I think it's the thermostat that needs R&R is that the only coolant drips I can see are coming from there.
I'm replacing the thermostat today, but it's tough going. Even with the fuel tank removed, there is almost no room to work. Removing the airbox will allow a smidge more room to swing a (stubby) wrench. I really don't want to remove the throttle bodies.