OK--Now I think I understand your process. I did,however,somewhat mis-speak because Python can assign classifications to elements and therefore the associated properties. It can not create new classifications.(It can create a new classification XML file) This would eliminate your necessity of having to manually attach your new classes to the target elements. It can assign property values to targeted elements, either directly or by reading a Excel file,once those elements were classified as you are doing.
However, the point is moot, since 23 can not run the current version of Python. I assume 25 would contain all the capabilities of 24 but I have no way of knowing.
Your approach is entreating and i think a Python app would greatly organize and simplify it. The point is not to be a Python programmer, others can do that for you. But to control the project through generally understood software such as Excel which allows a manager to pre-configure the projects materials, material and object specifications, builder's notes and, of course, cost calculations (somewhat eliminating expressions).
The process is now fairly simple and straight forward, but, would require you to upgrade to 25. When or if you get to that point I'm here to discuss the capabilities of any potential Python automation. I think you would be pleasantly surprised.
Windows 10 - Visual Studio 2019; ArchiCAD 26