Hardware » CANRec

The aproach with hirarchical schematics should help.
Buildingblocks

Works. Its a difference if the schematics is embedded as hirarchical one or opened directly. This is valid for Kicad 5.1.5.
In Kicad the individual reference is stored in the main project file.
All common schematics can be saved anotated.
Removing annotation will remove them for all projects.
Keep projects in sync as hirarchical schematics hold a lot of project related info which can lead to merge conflicts.