My KTM 500, has over 18,000 miles, 360 hours on Valvoline 20w50, doesn't burn any oil, never has, all original motor still in mint condition far as I can tell. Mine sees offroad to 100 mph sweepers every ride.
I ran Castrol 4 t, one run its a nasty oil. Didn't care for it.
Redline oil your not going to improve much over that oil with anything else extreme performance wise, but unless you can get 1000's of miles off an oil change its not cost effective. A 500 race motor requires sub 1000 mile intervals (which frequency of change is far more important, than the extreme limits that an oil can do.).
shear doesn't mean wear, but maintaining a 40 weight is ideal for cam lobes, either supplement a bottle of 20w50 with your 10w40 or run straight 20w50.
Having put 40,000 mile on a DRZ, I can tell you that you need a good film strength for lobe wear. BTW that motor was all original too, and still running mint.