Good question, @vlanard. Unfortunately, the Google v4 API copyTo function we use to add and remove templates from spreadsheets in the Tiller Labs add-on relies on a broad permission. To offer the sheet insertion and management functionality, “full access” via the https://www.googleapis.com/auth/spreadsheets scope is required.
We do not use this broad scope to access YOUR other spreadsheets. Rather, we use it to access OUR master templates and insert them into your active spreadsheet.
We anticipated that some users would be reluctant to grant this scope so we have bifurcated all core subscription services into the Tiller Money Feeds add-on which we strive to shoehorn into the much narrower https://www.googleapis.com/auth/spreadsheets.currentonly scope.
At this time, we are only able to offer the free & optional Tiller Labs add-on with the broader scope.
Randy