We have a custom basemap that we serve from our on-premise Portal. It is an image service. The image service uses the same security as our Survey123s.
Creating a TPK using the content in the image service creates a package that is over 20GB (and takes a week!) - making offline use of it impractical. Besides, there is full wireless connectivity throughout the study area.
What we'd like to do is for Survey123 to consume this basemap as the default map for when users collect their geolocations.
Is this possible?
Again - not offline, no TPKs.
The map in Survey123 can only use tiled layers in Web Mercator projection. If you can cache the image service, that could then be used by customizing the map types of the survey (much like the setting for a TPK).