Nice route,
... except why not go through Glenfarg instead of the M90?
New route.
It means going through Kinross and Milnathort first, then turning off on the road to Glenfarg just after you join the A91. Lot of nice corners on that road, especially between Glenfarg and Aberargie. After that it re-joins your route on the M90 at Bridge of Earn.
I know the thread title is Sunday Bimbles, but I'm sure you've done Saturday ones. So which day is it?