Would greatly appreciate responses!

Have a split level, recently painted aluminum siding, but 3' stucco from ground level up to siding which has couple coats of paint. I want to have a stone veneer placed on it. Mason said paint has to be either power washed off (if it does come off and much easier) but if not, the paint needs to be sand blasted off! Seems like a lot of work and money and mess.

What is the general rule of thumb here? Appreciate responses!

Paula