I am the bandit!
I steal eggs and raise fry!
The trap will not separate the fry from the tank water.
IMO to use the MB you need them to be in their own container with their own water and airstone.The MB keeps the eggs from going to fungus.
A Tupperware container or glass jar can work , and if you float it in tank then you will not need another heater...
I have had angels raise fry so far but never completely...Even with only two breeding pairs in a planted 120g!
Most won't when other fish are in the same tank IMO? They will eat their fry before the others do[fish logic???]!