My request/ requirement is to be able to upload or plan a route in cycle.travel and then display Drinking Water POI's along the route to be able to research and record as waypoints. Similar to your camping/ accommodation option.

Unless I'm misunderstanding, that is already available. Public water fountains already show up on the (CT) map as a green square containing a white drop. (They can appear and disappear at different zoom levels).

You can add a Viapoint at, or close to, the symbol and write a note. This note will appear in turn by turn directions on gps and paper. 

However, I believe it can get complicated between different file formats (gpx/tcx) and individual units so the best bet is to do a few tests. 

This feature was invaluable to me last year exploring Spain in sweltering weather. 

But be warned: depending on where you are public water can be in short supply either due to weather or the after effects of Covid. 

I guess my request was based on the program locating and highlighting them for you rather than having to zoom in and fly along the route to try and see them. 

On a 1700 mile route across France or across Europe thats a lot of zooming in and scrolling along to do. 

If the accommodation and camping POI's are recorded in the program then to change add a search function shouldn't be great to find water POI's.

Interesting idea – I’m currently roughly plotting out better POI handling so this would chime with that.

I think it might struggle to realistically find all the water points nearby a 1700-mile route – that’s a lot of POIs to show in one go. But it could potentially have an option to find water points near a given location, much as the current accommodation and e-bike charging options do.