Consider the function
which is called for every child in sortChildren:
It will call most of the time
which, for every wildcard name filter given to the model, constructs a QRegularExpression, and compiles it !
In my use case I have a fair amount of wildcards, coming from plug-ins to my software which make some file extensions visible or not in a QFSModel. When sorting a hundred files, this blocks the software for 4/5 seconds every time.