I want feature light and navigation heavy.
I dont stick to a route ,its just a general wander based on specific trails long the way.
I must derail this thread again, sorry, Ed!
Chris, it looks you do not need the GPS navigation at all; you need an excellent map with your current GPS pointer. Let us do a little speculation here. Assume you equip yourself with an older -- big screen and inxpensive --smartphone. Mount it in something very solid such as a QuadLock. Try Komoot in the totally free mode (it will certainly work free for one Region, your home one). The great thing about Komoot is it has excellent cycling maps including the UK (Komoot is perfect for Europe including the British Isles). (Yes, you need to make an account and log onto Komoot, same with the PC).
Go to Record. You probably
don't need to record your ride at all, only the Activity Type such as Cycling should be selected to use a correct map. Click the "navigation arrow" on the on-screen menu. It will detect your current position. Then just ride. The GPS marker will move as you ride. As it is a map, a very good map, you'd be always aware of your whereabouts. You would be able to zoom in and out as well as pan the map, so you can orientate yourself. No need to Record, no need to Navigate.
I am only unsure how much you can get with the free license. Perhaps it is 100% your needs?
Now, the PC. After you have logged onto Komoot on the computer, you can go into the Route Planning mode. Again, no need to Plan anything. Just scroll to the area of interest and peruse the map. The Route Planning mode will display hundreds if not thousands Point of Interest as well as Heatmaps
and even the actual photos of the trails! So you can explore the area before even going with your van there! The heatmaps show where other people have actually ridden. So if some bridleway has nobody riding it, expect trouble

You could be of course the first to explore the previously unexplored trails! Note: Komoot even displays padlocks where you are
guaranteed not to come through
Now, again, I'm not sure how much you could use Komoot totally free. In the worst case scenario, it is a one time flat fee to Unlock All Regions and that's what anyone with more serious needs than yours does.
Cheers!
The Record mode with no recording on, Cycling Map, zoomed out. The map already shows a Point Of Interest, the Moszna Smoke Stack!
My closest neighbourhood, Komoot Route Planner (PC). "The Great Chimney in Moszna" and "Concrete Tower with a Face" is the same thing
More valuable is the information you cannot ride a road through the cement plant. Also, nobody has warned you the access to the lake is forbidden
P.S. Green lines are for bike paths.