@Mike-Denning I am a long complainer about the connected app and it's implementation on the 6.5in TFT as fitted to the GS and GSA (I've had one of each). Over time it has got better but was never quite there.
I now have the K1600GT (with 10.25 TFT and map-view of course) and had everything updated a few weeks ago (TFT and app) and I would say the connected app is now 90% there.
Here's my LIMITED experience with the two... (Gold membership will be necessary for all functions)
The key I find is to plot a route using Tom-Tom maps (as this is the system the Connected App uses) with 'just' enough Waypoints or Via Points to ensure your route cannot deviate. (Place a waypoint just after a junction for example to ensure the route will go that way). MRA does have a function to add waypoints automatically, but I find that it adds too many, so I either use the 'reduce waypoint' function (where you can then choose how many you want), or just do it yourself. If you use an automated way check they are a) on the actual road, b) placed logically.
Export the file as GPX 1.1 (Route, Track, POI). When importing into the Connected App this will offer you the three parts (Route, Track, POI), deselect for now the Track and POI ones, leaving just the route one. This will have x number of 'support points' that matches the Via and Waypoints in your MRA export.
When you bring that in it will look like it has 'direct lines' (which it does, point-to-point). See below:

Now press the button to the left of 'Go' (with the 'play' like symbol). This will offer you a sub-menu of how you want the route plotted. Select 'From start point'. (see below)

This will plot your route honouring the 'support points' you entered. (see below)

It would be great if BMW offered an online 'viewer' as it's then tough on the phone, but try and check the route has in fact plotted as you think. It should as Tom-Tom, should match Tom-Tom.
The TFT does now give you the option to skip-waypoints and if not you just automatically fire through. Any Via Points on the route will of course 'announce', so I often add Via Points called 'One Hundred Kilometre Marker' for example.
I started this with LIMITED so bear that in mind, but I have a test Normandy trip upcoming on 29th and then a month from UK to Nordkapp and back via Finland, et al.
As Alex also says, with the app if you're bored you can see bike telemetrics, such as see how far you lent left and right, top speed, when and where you triggered ABS or traction control and such. It also stores any photos along the route.
If you select the 'track' option on import, you will get no announcements but 1,000s of 'shaping points' that will ensure you don't deviate from the route. That is another option we've used before and it certainly works.
Hope this helps?