An exported canvas app which references SharePoint lists is a pain to import into a different tenant.
Let's say the app references 15 lists from the same SharePoint site. After importing the app the developer must delete all list references (one by one) and then add them back one by one to a SharePoint site on the new tenant.
In the import screen there should be an option to point a SharePoint connection to a specified SharePoint site on the new tenant (or multiple sites, if there are more than one connection in the exported package).
This is getting close. There's a mention of it towards the end of this blog.
https://powerapps.microsoft.com/en-us/blog/announcing-the-new-solution-import-experience-with-connec...