Powder coating looks like a decent route just curious how touch up would be.
Finicky…
The good news is that, being the frame we are talking about, not an axle, or a bumper, needing touchup is not a common problem to run into.
However, if you make changes to it after the fact, then you run into all sorts of the usual suspects.
Powder coating is typically thicker and if you gouge it, it leaves a deep recess. Not something you simply rattle can spray over and hope it matches.
You have to fill the gouge first, then spray it.
And still hope it matches!
And the other thing, which is always the first consideration, really, is whether or not you’re actually done making modifications to the frame before you have it powder coated.
That’s when you find out that you forgot to weld on the new shock mounts, or modify, the radius arm brackets, or repair a crack, etc.
You have to have the build basically complete in your head with no ad-on later gotchas before you commit to a powder coating job.