I’m looking at this myself as I’ve gone through 7 pairs of BB30 bearings in my 29’er Stumpjumper’s PF30 BB in the past 2 years, doing mild XC trail riding once a week and being gentle cleaning the bike
I’m convinced the nylon PF30 cups and BB30 bearings are not aligned properly when installed, as my last set of new bearings have lasted less than 9 off-road rides before going rough when the crank is spun
thankfully, I’m a bike mechanic with access to a very well equipped workshop, so it easier to deal with these issues
since the SRAM crank is now wearing out (arms looking very shabby) I’m considering moving to Shimano HT2 cranks with the native 24mm axle, and have been highly recommend the Praxis Works convertor by many riders and industry contacts.
Its around £60, with quality bearings, reduces the I.D. to 24mm for the Shimano cranks and most importantly has an expanding “collet” design which grips the BB shell as its tightened together; its also a machined aluminium alloy unit which should ensure the bearings are held parallel relative to the crank axle, unlike the Nylon PF30 cups…