There have been experiments by several people (including myself) for this, and some times they seem to work, but then break in a later KiCad version.
KiCad also does not support “design blocks” yet. I am guessing that things like this will become supported in a few years time. Things like handling the Refdes and netlist is difficult and some way to handle duplicates must be implemented. On top of that, KiCad is still a relatively small project and there are several hundred feature requests open on gitlab. (Including a few for design blocks and multi pcb projects).
The plugin Kikit allow you to have : one schematic but multiple PCB. And use the plug in to separate each pcb to end up with one pcb per file for gerber and BOM production.
This is quite useful to have the lain board an its front panel in the same project and the same schematic.
This is my approach to Kicad organization and, I set different Worksheet’s for PCB and Schematic’s. After setting the Worksheet, lines of text get created. Then, I edit the text to link a different worksheet.
I do it this way so each can have different Comments/Graphics/etc and retain them.