My experience of the recent slowing down when launching applications
is that it is related to the new test for sandboxing.
I noticed that even if an executable is excluded from the
sandboxing feature it is still slowly launched ! The file must be
excluded from the whole real time protection to recover a fast launch.
Yes, this seemed to work for me too. Adding the program's dir to the exclusion list got the load time back to normal (I also have sandbox mode disabled).