I'm afraid that the Extend X/Y size to area mode used for the roof libraries always creates a rectangular array. If you need the the verge to follow the angle then the only workaround I can think of would be to use L1S arrays and create a spline for each course of tiles, but I understand that would involve a bit more preparation.
If however the roof can remain rectangular in plan, you could turn off Slice for the verge segments. You'll then need to open the Macro and change the Generator's Clipping Area > For No Slice parameter to Preserve. This will prevent tiles being sliced, even if they cross the boundary of the clipping spline.
Thanks for the suggestion about the verge offset. I've added that to our wishlist to improve the styles for a future update.
I hope that helps,
All the best,