The priority settings in Miscellaneous #2 for Par2 (and possibly also those for Unrar and Decoder) don't seem to have effect anymore.
This is especially noticeable when a post has (very) big parts. Even altbinz gets a "not responding" tag from Windows for a little while.
Task Manager shows par2.exe always running at normal priority.
altbinz 0.46.0.1
Windows 10 v1803 x64