Develop Persona should work exactly like in Lr.
Those kind of developing saves disk space and give ability to edit image any time non-destructively.
A current kind of snapshot ( a raster image ) should be generated as an output for Photo persona automaticly.
But editing process in Develop Persona should recreate at beginning whole tree of steps that user did here previously ( like in Lightroom ).
If you make it work like this the Affinity PHOTO will be the best image editing software ever. :)
I am counting on you !