How are you gonna get it in the top of a sealed conical? Unless you are using a plastic conical. My conicals are 7 bbls and pressurized though so I may be thinking on a different level. But even my blickmann conicals with the pull top lid were impossible to skim any foam from especially squeezed inside of a fridge/freezer.
Regardless, much of the "braunhefe" will get stuck to the sides of the fermenter anyway and unless you are open fermenting or in a bucket I don't see an easy or convenient way to skim and I personally feel it is a very, very minor difference. I doubt many breweries are skimming from inside their conicals.
The lid on my SS conical is a sheet of clear plexiglass, thus it is somewhat of open fermentation. It stands 5 ft tall, so it doesn't fit in a fridge. You are talking me out of skimming, but I'm having trouble resisting the urge.