@Brian-McG Yes, the Toolkit compare is a handy function. For safety, you definitely want to place waypoints where the other base maps agree.
Having to worry about the accuracy of a base map (any map) is a new concept for me. I've developed hundreds of routes in Basecamp (HERE) and inRoute (Apple), executed on Garmin GPS units, and have never encountered this. I know -- different environments, different behaviors.
I don't plan to use the MRA Next app again anytime soon, so at this point it's a non-issue. As I type, I'm setting up a new Garmin Zumo XT3, and that's going to be my primary route execution layer. Like I have been doing with my Zumo XT, I'll execute routes developed in MRA using the OSM base map. I've been snake bit using MRA HERE too many times.