Under warranty?  Just bring it back to the dealer and let them do the diagnosis now that you know your work is good.

This is now resolved.  Dealer replaced the crank layshaft seal behind the belt cover (warranty) and all is well.   [moto]

My oil cooler installation was good.  Just a coincidence that the layshaft seal started to leak at the same time, or rather some subtle difference in internal oil flow or pressure as a result of the new cooler made a marginal seal fail and leak.  The foot powder was really key in determining the origin and also ruling out possibilities.

BK

Glad to hear you got it resolved. I love the foot powder method. It is now in my bag o tricks!