@ptrdvrs ok, I believe I have understood bit better...
If you have a route, you can open via left side menue the internal POI section and select a POI category - may a Coffee shop. If you are zooming into the map, icons of this POI category will appear on map - and you can see, if in the preferred area, such a POI is close to your route.
If you click on such an icon in map, you will be asked by popup window, if you simply want to add this POI as only POI to your route - or if you want to add it as POI AND as route point.
As only POI, it will be visible only in the map and in the manageable list.
As POI AND route point, it will be visible in the map as POI (and in manageable list) as well as route point, included in the route and route point list.
If you transmit it via gpx 1.1 to garmin, the file includes POI, route with route points and track with track points. And Garmin will import all (POI as favorite).
If you have a route, you can open via left side menue the internal POI section and in the tab "manage" you can enter your own POI, selected by position in the map. But unfortunately thus will only be a POI in map - no way to include it as route point. If you need it also as route point - in this procedure, you need to enter a route point manually nearby.
In all 3 options:
POI selected from internal POI section
POI selected from internal POI section, incl. set as route point
POI created manually
every time, the POI will be transmitted to Garmin-XT into favorites. The route will not include it (only in case 2), but in your scenario- you can stop navigation, select the POI out of favorites and let garmin navigate to.