That device expects a sufficient power supply to provide its maximum output, so the moment the panel can't supply the set voltage and current, it shuts down. There will also be no MPPT function whatsoever.
If you set it to a voltage and current that is < 50W, then it will work when the panel can meet those needs. It will never output more than 50W, and if the panel can't supply 50W, it shuts down.
For $10 more for the ECO-WORTHY, it makes a lot more sense to go with a MPPT charger designed to boost.
Correct. Almost none are. That's why I started this thread.
Victron MPPT require +5V (0A, Voc) above battery to START working. PV must remain +1V above battery voltage to continue operating.