Doable, I think
Schematics are written by verilog code finally
You can see it in project.v file
But I don't know how to do it, of course
The schematic capture one would think is based on some "standard",
maybe if you file a CASE you might be able to answer the question.
To file a tech case -
“Create a MyCase”
Doable, yes, the schematic is represented in file you can open it and the whole build process is based upon several files in the devices folder. Although, doable, I think it will require a lot of research to build it from scratch as it is not docummented (at least its not been made public). I think you could start with a base project build on Creator and then use pyton to modify the project according to your needs.