I apologize for reviving this old tread. The subject does mention the DataGrid, but after reading it with the PDF generation timeout problem in mind, I thought that was the main subject.
And I apologize for crying frustration too quickly. Adding the serialization didn’t take days, it was just an hour of work (thanks to the test driven development that allows to work and test the serialization in PyCharm and allows to store all the required data in one singleton, parts of which were already serializable).