Fragging Duncans

[Rogue951]

I have a duncan coral that's growing in a ball outwards.
From 4 heads the size of a marble it's now bigger than a golf ball and shows no signs of branching.

How, if possible, would I frag this? just cut through and let it heal?
or just let it go and see if its going to branch?

The ball shape is just getting a little odd to place without smothering some of the polyps.

Thx