If you have a few quid free for facing, spend it.
Having a smooth, flush and parallel metal surface for the bearings to sit against is likely to extend the lifespan of a BB by preventing any deformation of the races and pressure spots. It’s also likely to stay tight in the frame with less force, meaning you are able to fit it with lots of anti-seize [not grease, esp/ not PTFE grease], not over torque it and still have it come out again without a scaf bar and the biggest bloke in the LBS sitting on the end of the lever.
The threads will also be chased, so that’s handy as well.