Beryl is 7.5 - 8 on the Mohs scale so not so soft nor brittle. Although struck in the wrong place even a diamond will take damage due to the cleavage caused by the individual crystalline structures.
Beryl can be cut into almost any shape and give a good to excellent lustre when polished. I have Emerald in every possible cut and even a couple of carved ones.
I think the final decision a lapidarist takes depends on the rough when they examine the inclusions, colour zones, cleavage and what a customer wants, nothing to do with the specific properties of Beryl.