Ed, i've never used a store bought "thermostat eliminator" before. But I have cut the lower cage and removed the spring and plunger from stock ones. I use to buy a lot of old cars that had been sitting for years. A lot of times the thermostat would stick shut or only barely open. Knock the center out and drive. If i kept them long enough, come winter it would remind me i needed a thermostat cause the heater wouldn't warm up much.
I guess thats the same as the store bought, summer never a problem. You need that washer/ gutted housing to restrict the water flow, if not it will curculate too fast thru radiator and not cool....over heat.
That's my experiance anyway.
Haha, got me to thinkg back. Every late fall when I worked at the service station in the 70s, we still had old folks that would bring in their cars to change to winter thermostat (180-190°) and put on their winter snow tires.(already mounted on wheels), and oil to 20wt.
Then come spring, change back to 160° and summer tires, 30wt motor oil.