Fuel Planning

Guess it depends what you mean by easy?  You can bring up a route in BaseCamp and look at it's properties, select the Route Directions tab and then click on a point at 200 miles, see where it is and add a viapoint etc etc.  Or am I misunderstanding what you're after?

The best way would be to automatically add a waypoint every 170 miles on the trip route so I could go to each waypoint and add a fuel stop. Seems the easiest way that I have found is to hover over the route with the pointer, find the mile point that I want and search for a gas station on that zoomed area.

Well there is no way to do that 'automatically' I'm afraid.

You would think it would be a no brainer especially for the trip planner mode. "Search for gas stations every x miles on my route" Seems like a fundamental part of planning a trip!

What I'd suggest, I have a Zumo, is to create your route - don't worry about fueling stops at this point. Transfer the route to your device. Now I know this will work on a Zumo, I would begin navigation of the route then select to search for gas stations. The device will list possible candidates - select and then find the same spot in Basecamp. Repeat for the next and so on. Not totally automated but it is one method I've used along with what has been suggested.

You can download and use the GasBuddy app. New feature is put in your route and will find gas for you.