When it comes down to it - the "rag joint" style of sprocket mounting is a stop gap, half ***ed method at best TBH, I'd hate to compound alla problems with sprocket alignment w/brake issues too... not to mention the probability of rotor fouling w/chain oil.
Jim makes an awesome adapter that bypasses all that BS and it seems to me I saw a disk adapter around sumwheres... bedanged if I can remember where tho lol