Meta Quest 3: How reliable are the virtual anchors for outdoor terrain?

I am building an app for Meta Quest 3 and have to map specific locations in an outdoor area ~5 acres.
The app will be showing information when the user looks through the AR kit (passthrough) for a particular location.

How reliable is to use the virtual anchors for mapping those? My concern is that since it is outdoor the Scene API may not always recognise the surroundings and notify my app. If anyone has experience with similar issue would be more than grateful to share that please.