I'll throw my tuppenceworth in to say that if not too much work this would be a useful tweak.

However, I can see issues with older routes that may be recalculated if the routing is tweaked automatically?

I think it’s a good idea. Exasperatingly it’s not something I can do right away for a handful of reasons; c.t doesn’t always calculate the elevation (only if the user requests it), it doesn’t save the elevation with the route, and the iPhone and Android apps aren’t yet capable of calculating the total ascent (which is a scary big chunk of code!) so couldn’t save it with the route. All of these are things I’d like to address, probably starting with the apps. Once they’re done I can take a look at adding this.