You could do it a million times, it would still be a shadetree shortcut and the wrong way to do it. Moving the perches is easy, and shouldn't even be all the expensive if you have to pay someone else to do it. Slotting the perches will leave a portion of the spring unsupported by the perch. Whether you notice it or not, there is an effect. If it didn't matter, the factory would save the metal and make all the perches smaller than the width of the spring.
