Hello Hugh

No problem with putting a few hills on your route and considering them to be a "fine weather alternative" As Vanessa says better to have the option on the day if you are minded to go up some. From a Control point of view we need to have any hills you might be on noted on your route sheet as the main route with an FWA which can be a "feeling weary alternative" for if you don't feel the urge on the day or the weather prevents you.
As these would be your first Munros we'd suggest keeping to the relatively simple ones that are in effect "in the way". Mount Keen and Lochnagar spring to mind - good paths up and down both of them.
If needed, you can change your route during the Challenge but you should let Challenge Control know your new plans first in case there are concerns about you. If they need to call the emergency services they need an accurate as possible idea of where you might be.

Ali & Sue

PS Our "spy" network may not be quite as extensive as Vanessa suggests . . . . !!!:grinning:

You shouldn't allow us to think that!

Vanessa, don't take any notice - they are just lulling you into a false sense of security.