Ben Weissman shows how to find duplicate indexes using Biml:
This little piece of Biml will check all your tables for indices sharing the same columns.
It does not generate any SSIS tasks etc. but might be a good starting point to build your own Index-Monitoring or Index-Clinic – because Biml is NOT just for SSIS
Depending upon your definition of a duplicate index, this might generate false positives. Regardless, it’s a nice way of showing that Biml is about more than SSIS.