Can I use Savable Data Pages to delete an instance or remotely purge an instance from another System of Record?
We don't see this quite so much as often the 'delete' is a special kind of update. However one of the paths the Save plan can take is an Activity, which could have an Obj-Delete or call a Connect-REST using the DELETE method.
Stage a property on the Data Page that is set by actions performed in the User Interface to indicate whether the next save action for that instance should be (Create, Modify or) Delete, so that the When conditions in the Save Plan can check whether the Delete Activity should be performed.
However, don't ever use Commit in your Save Plan activity as this will commit deferred saves that are unrelated to your Savable Data Page. Investigate the WriteNow support for the Save Data Page options if your Save Plan database changes need to be immediate, but ideally treat these as any other deferred saves.