IF rpms increase with same power input - the load on the motor has decreased
same on a glo setup-or gas
A glow setup which unloads in a dive is NOT making more power -it is simply under less load
Some guys lean out glow setups sothat tey screm inshllow dives but are lean in level flight and they sag in sustained climb
this is typical for an IC engine
ideally you want max horsepower in level flight and finding prop which does that is cut n try.
Torque can beincreased using a tuned setup -which increases max hp - rpm
again cut n try
On control line the pipe setups were set so short that the plane had to be 'whipped to get it up to tuned resonace rpm- then the models would take off like a goosed goat - the mix was always rich to allow th settingto be correct when it hit piped rpm
You cant get more power with less fuel - can you?