Can I use a Savable Data Page that saves its data across multiple Systems of Record?

Yes. The When conditions in the Save Plan are all evaluated, with all Save Options whose When condition returns 'true' to execute. This means multiple Save Options could fire when executing a Save for the Data Page.

This complexity could be encapsulated into an Activity, if required.

Discussion on this topic was sought from the LSA Data Excellence (Pega 8.4) webinar conducted in July 2020. The webinar and its full set of discussions that arose from it are available at LSA Data Excellence: Webinar, Questions & Answers.