premium ediscovery custodian data sources

to confirm, adding a custodian in Purview premium ediscovery - this does not add any "Team" SPO sites (SPO sites not connected to Teams).  If a customer wanted to know every SPO site a custodian has access to - would this be possible to write a script?  Or, is the best approach for a discovery admin to just do a broad search of ALL SPO sites and see what gets returned from this broad search?