We get an enormous volume of feature requests, and the best way for us to prioritise them is to understand why they are necessary. If someone says something like "please add a feature to make it look like objects are being juggled by a clown!" without providing any explanation why that's important. Then I have to weigh that up with say 100 other feature requests, and I just wonder "what's so great about making objects look like they are being juggled by a clown?" It doesn't sound essential and there was no justification, so I'll probably do something else first.
I can't go and make a game that needs all 100 feature requests to see for myself, because there are so many requests, and they span genres, development styles, markets, platforms, environments and so on, I've got no chance. So I listen to what people say, but only if they describe why. If you look through this thread it's only people saying "please add it", and the only justification involved CPU usage which doesn't make any sense and wasn't backed up with a .capx demonstrating it.
So if you want to turn an erase mask effect off, why wouldn't you just hide the layer instead?