Personally I use Syn3 in engine and B&M Trick Shift in my primary/trans. The B&M was recommended by clutch mfg when I replaced clutch. I used Formula + prior and never had any problems. I was advised NOT to use Syn3 in primary as that was too slippery and some have experienced clutch slippage. That said, I would caution against using a "regular" type motor oil in the primary. I would use something that is compatible with friction plates for your primary.
"If you're looking for sympathy, you can find it in the dictionary between shit and syphilis."
I use Amsoil 20/50 in my 95 883 Sporty and it is my understanding that my bike has a dry clutch so I even add Tufoil motorcycle engine treatment and I have never had any clutch slippage problem. The bigest surprise was how much easier the trans shifted no more clunk except going from neutral to first gear.