"I have lined out limit switch for short durations ( middle of night
and heat
needed), but I consider this a fire hazard over long term, plus unit
runs
continually in that mode."

Can you use the fan switch in your thermostat instead of doing this?

And where are you getting $10 limit switches from? I thought they cost
more like $40?
Link?

I had a problem with mine once, and it turned out to be the crappy push
in terminals on the switch. Replacement models have both the crappy
push in terminals and regular screw terminals (like the back of an
electrical outlet).