I really like the lightbulb feature, that helps renaming parameter names in functions/methods.

What I do not like is, that it breaks formatting of the parameter listing of the function declaration or definition (depending on what to adapt to).

Starting point:

#include <QDebug>

// declaration
void foo(
      int i,
      float f
      );

// definition
void foo(
      int i,
      float f   // put the cursor on 'f'
      )
   {
   qDebug() << i << f;
   }

int main()
   {
   foo(1, 2.);
   }
 

Now put the cursor on 'f' and choose Context-Menu => Refactor => Switch with Previous Parameter". The result is ok.
Now click on the lightbulb to "Apply Changes to declaration".

This refactoring leaves the declaration in an ugly shape.

#include <QDebug>

// declaration
void foo(
      float f
      ,
      int i);

// definition
void foo(
      float f,
      int i
      )
   {
   qDebug() << i << f;
   }

int main()
   {
   foo(1, 2.);
   }

So, in the declaration I would have expected to just see the lines switched:

// declaration
void foo(
      float f,
      int i
      ); 

As the declaration is typically in another file you would have to switch to the file and fix the formatting.