I fly my own L-21B (an ex-military Super Cub) 150 HP - O-360 engine.
My personal "policy" - really none applies - as I fly in the open country...
Vy initially, to 500 AGL, then Vx+10 max climb power or less.
If in urban areas - Vy to 800/1000 AGL (if no suitable fields straight ahead).
This in case a 180º turn to departure runway is considered.
Obviously - many options - consider your environment and obstacles.
xxx
Super Cubs 150 HP are sometimes operated at "J-3C65" power - Engine economy...?
Seen that note in old PA18-150 owner manuals.
Throttle set to 2200 RPM at takeoff for training.
I think it should not be recommended in urban areas with obstacles.
xxx
Happy contrails