Have project specific user dictionaries
Under Projects Pane in newer QtCreators project specific settings can be setup.
Do you see a chance to give a project specific user dictionary, that could be part of the source version control, so inside of the source folder.
A typical scenario is the in a project "specific" language is used, that might be outside of "normal" english terms. However in other project, these "specific" words might be just wrongly spelled. Switching by hand the user dictionary might be cumbersome.
It might get even further: It might be helpful to have a user dictionary per project folder. In Qt you can have Subdirs projects with e.g. one EXE folder and some DLL folders. The DLL folders might be shared by other projects. So wouldn't it be nice to have a user dictionary file per project folder? You then could add a specific word to the specific user dictionary depending on the location of the file: If foo.cpp is part of FooDLL then fixing the word in this file leads to an update of FooDLLs folder user dictionary...