I've read the "benefits", and I've seen how mine is installed. But is
this really practical or at least optimal?

I have a 100 BTU furnace to heat 1700 sqr feet mainfloor and about
1300 basement (partially finished). The 2 stage functionality works
like this. I have a normal programmable thermostat. On the furnace
they installed a "timer". After the thermostate turns the furnace on,
it will run at low heat (3 burners) for 1 to 10 minutes (depending on
the manual setting of the timer). After that time it will kick into
high heat (2 more burners). It runs at high heat until the thermostat
kicks it off.

Theoretically, on milder days, the low heat will be enough and it will
never go into high heat. Then for the fewer cold days it will crank
up the heat. However, we set the temp to 65 for the night and 69 for
the day. So I can be sure that in the AM, it will crank up to high
heat to get to 69 as that will take 30 minutes or longer.

Does this really matter? Would a 2 stage thermostat make a big
difference? This all seems pretty questionable to me. Sounds like
marketing hype.