Perhaps this should be 'wishlist' instead. When parsing a large project, or one that includes large external libraries, parsing can take a minute or two. Until this is completed, various false problems are displayed (undefined variables, unknown functions, etc). The highlighted lines and words caused by this are quite distracting. This can also occur after initial parsing, e.g. when adding an additional import. It might be better if problems were not highlighted in the text while files remain to be parsed, since in almost all cases they're false-positives.
I didn't add this to one of the Language Support categories because it affects several (all?) of them - C++/clang, but also python and QML/JS that I use. 'General' might have been wrong, but the new category is too narrow.
Thank you for the bug report. As this report hasn't seen any changes in 5 years or more, we ask if you can please confirm that the issue still persists. If this bug is no longer persisting or relevant please change the status to resolved.