I did a "narrowing" job on a stock SW mainspring mostly for curiosity to see how much it takes to get the strength down to about where a typical "reduced power" spring is..... and it took a lot of grinding. It was removing more metal than I would and still feel confident about the spring's integrity.

As for bending: you don't have to bend them much and if you spread it over a little distance (and use a curved piece to bend it on), the spring has no problem. I have done it on at least a dozen of my own smiths and never seen a spring fail or even "walk" to where it needed to be retensioned.

As for grinding strain screw ends..... hate that because it's non reversible and you need a micrometer to know what the thing is cut down to.

I like the Wolff ribbed springs for function but the groove in the spring tapers the end of the strain screw effectively shortening it by tapering tip of the screw. Pain in the rear to have to keep replacing the screw to maintain spring tension.