Hi Husky

I actually prefer the way it is, otherwise I may insert a block persistently in a certain 'flipped' way.

I guess its a matter of personal taste here ;)

Hi Clive,
I said it isn't Highlighted - I don't said it is not working! What means you have never the visual info about the "Flip Status" what brings you in danger to insert a block persistently on an unwanted way ... ;-)

I don't just think it is only a matter of personal taste here - it's for me more a matter of Informational Feedback and consistency of the Program. E.g. the Insert Function of the clipboard is already working with Highlighted Flip buttons ...

Husky - yes fair enough, good point!

This is intended behavior.

Basically, block inserts cannot be flipped (only scaled and rotated). QCAD achieves flipping by changing scale signs and rotating.
E.g. clicking the horizontal flip button is just another way for changing the sign of the scale factor in Y and applying a 180 degree rotation. The flip buttons do not apply an additional operation (like the flip buttons of the paste tool). They are not switches but helper tools to apply a flip by scaling and rotating.