Just keep an eye on the split in the seat tube. Once this is touching, there’s no point continuing to tighten. Both parts have some manufacturing tolerance it’s not uncommon for them to need a shim. Is it the Thorn post?
I bought a secondhand frame with stripped threads so it can happen, though not sure how. It was no big deal, I just used a longer screw and dome nut.
It is a good idea to remove and grease the seat post from time to time, doing the bolt at the same time makes sense.