My Race mechanic friend has had a lot of trouble with Dyna's, coil and pickup failures, and pickups slightly out of place making it hard to time perfectly, 2 cylinders would be perfect and 2 slightly out. ....
Only had one pick-up fail and one coil in 30 years of using these Dyna's and that's with over 20 or more bikes fitted with them but the amount they sell there's bound to be a few duffers get through and it's sods law someone might be unlucky enough to get more than their fair share.
The timing of the paired pickups shouldn't be an issue though as they are individually adjustable on the back plate via the tiny cap head screws and even though they are close from the factory they always need a tweak to be spot on.
Dyna went through a bad period in the early 2000's , they had a huge amount of failures, there are still a fair amount, My mate deals with a lot of dyna's and has had a lot of failures, its well documented at distributor here. Funny thing is, I have 40 year old Dynas that are still going, I suspect they are all being built offshore in China now..
I'll ask him in detail what's going wrong with them, I've seen a few of the dead coils though...