Never thought about starting a vehicle to keep seals from drying out. I've been storing my motorbike for years and that is on a stand so off wheels, and on a trickle charger. Bike is now 12 years old and I can't comment on negative effects of not starting it.
I don't even bother with draining fuel , I just use what's in the tank and never had issues.
Having said all of that, the rubber grommet to the petrol tank on my petrol strimmer did harden and need replacing, but that was stood for years....