The mast on my Nacra 18sq was perfectly straight but had a small dent in it halfway between the base and the spreaders.
I raced it for several years like that.
I finally got tired of everyone telling me it was going to break in the next race, so I fixed it.
I drilled a 1/4" hole into the mast, opposite the dent.
I laid the mast across some cinder blocks, with boards for protection, and placed a cinder block with a board directly under the dent.
I used a 3/16" steel rod as a punch and VERY CAREFULLY hammered the dent back out.
I plugged the hole with a 1/4" pop rivet & silicone.
Most people can't even see where the dent used to be.