I forget who Planet X use for their frames now but it's one of the well known factories, Waltly or Titan or something. So the quality is good and there are frames coming out of the same shop for double the price.
It seems Titan have packed it up, or at least shut down their client facing website. Shame really, they could deliver full custom at the price Planet X is charging for their Tempest.
My wife got a custom Titan this year. They briefly shut during Covid but they're still making them. We went with Titan on this build as they were cheaper than Waltly and had a shorter build time. I've got a Waltly and the experience with Titan was practically identical.
I forget who Planet X use for their frames now but it's one of the well known factories, Waltly or Titan or something. So the quality is good and there are frames coming out of the same shop for double the price.