I like the idea of your Royce/sq taper – I too have a Phil sq taper with servicable bearings. The Phil’s didn’t last long I have to say in my HT I used over last winter, plus the Middleburns have to said are a faff.
The XT crankset this BB is for is 4 years old and has been in as many bikes, it’s just so easy to maintain when anything needs doing, lighter and stiffer than the ‘burns.. etc