Hey #SQLServer folks. This took a while to code and test...and an eternity to run the TSQL scripts to completion. But it seems to work. The first iteration looks really promising.
In our biggest/busiest SQL Instance, I counted 17,732 INCLUDE columns in all non-clustered indexes across all databases.
Only 6,645 of them have query plan references in Query Store or the plan cache.
That's a lot of "over indexing"!
https://github.com/BeginTry/SQL-Server-Indexes-With-Unused-INCLUDE-Columns