okay to drill a tiny hole in the side of the thermostat flange to allow trapped air out without the thermostat being open
Yep, I've read that too. But, I believe the 1/8" hole should be in the TOP of the thermostat to allow air out with thermostat closed. If the upper hose runs all uphill to the radiator "burping" shouldn't be required.
Another neat trick for holding the hermostat in place is to attach a rubber band to the thermostat, run it out thru the end of the thremostat housing and around a pencil. When thermostat housing is bolted down, cut the rubber band and pull it out.