What product are you using? AppMon, Dynatrace, Synthetics?
Regardless if this is truly a SaaS I imagine there is very little monitoring (especially in-depth) monitoring that you can do as the provider of this service would be managing this completely on their end. Depending on what you're using there may be options such as monitors in AppMon or synthetic tests but even then I'd make sure there is no legal issue or anything in testing in that way.
This is Dynatrace SaaS managed Model and we have no clue what to do to get the SaaS based product stitched in for end-2-end monitoring. The products are all onboarded and they provide some dashboard to monitor, but do not want the silo monitoring mode to start in our environment. any links that document how we utilize Dynatrace to get this done or is Dynatrace stretched too far James?
I found some documentation on how to monitor SaaS applications with Dynatrace SaaS Managed.
Hope this Helps,