Well,
I have sucessfully sideslipped a pa28 and had no problems
I believe that there are certain machines that side slipping is an issue as various control sufaces are blanked but this seems to present no problem in a pa28.
I was taught c 1996 by my insructor to side slip
When working for a flying school side slipping was not in the syllabus
They felt their students should fly a perfect approach every time we all know in truth we all screw up and side slipping at times can be an extremely useful tool
.........Waiting to be shot down...........