Modern pages: possibility to add SPFX web parts to a page layout
Add the possibility to have a page layout with SPFX web parts declared in HTML, with XML or JSON inline.
This way we can build page templates, with desired look and feel, a predefined layout, and predefined web parts on it. It would be nice to have also editable zones so a power user can still edit the page, without completely breaking the pages as they were meant to be when they were provisioned.
Comparable with classic page layouts, but with new the layout definition, SPFX parts defined on it, locked down and customizable zones.
This will make it easier to create templated modern sites, and update them afterwards, without writing lots of code to checkout pages, add/remove/customize web parts and publishing them.
Tom Burke commented
+10 to the Anonymous comment from July 17, 2018 about locking down certain web parts and effectively creating "page templates" that can have content added, but where web parts and structure can't be messed with. This goes to the governance efforts we've put around our current Classic experience.
It would be great to have the ability to lockdown some parts of the modern page (not editable/removable).
We want our editors to be able to add, edit or delete content in a flexible way, but some structured content/parts should always be there, so these parts should be locked down/non-deletable....