Hmmm... It works for Well-Formed Check EPUB (F7) and for validation plugins.
For SanityCheck itself I haven't checked, since it's probably called every time we use Validation Results.
I'll test it during normal operation for a few days and if I don't find some unpleasant side effect I'll send the diffs so you can figure out the proper naming for the voids yourself.
In brief:
For plugins: PluginRunner [plugin name] -> MainWindow -> ValidationResultsView
For Well-Formed: MainWindow::WellFormedCheckEpub() -> ValidationResultsView
Code:
void ValidationResultsView::setNewValidationTitle(const QString &text) {
setWindowTitle(tr("Validation Results") + " • " + text);
}