I would think (altogether now....

) that when a manufacturer utilizes the PLEK procedure, they would take the fret leveling only so far after installation and then utilize PLEK to finish the leveling job as opposed to doing a complete fret leveling step by hand,
then utilize PLEK, unless they thought it was a quality control move (???). As opposed to the
Sweetwater approach to simply offer PLEK'ing a new bass on the showroom floor or warehouse as a $300 option.
I remember having both my Lull Jazz-style bass and my brand new Stingray Special worked on last summer. I had broken the nut on the Stingray (the 2nd day I had it....


), reglued the broken piece and had it replaced 2 weeks later. I took both basses to have the nut slots checked for proper string spacing. Out of the blue, I asked him to check the fret leveling on both passed. The 5+ year-old Lull, which was PLEK'ed when built, was still in proper fret level. The Stingray, which aren't PLEK'ed when built, was in good shape fret-level-wise, but he wanted to take "a couple of swipes with the file" to the treble side of the 14th fret just to shut me (speaking of himself) up" I hadn't noticed an issue and both basses played great before and after he worked on them. And he did say that I may have never noticed it. I believe that.
I've not asked the Lull guys about their approach to using the PLEK process when making basses and I wouldn't because of "in-house info" privileges. I don't care if they use golf course lawn mowers when leveling frets, it's no secret that the Lulls are some of the best-playing basses right out of the box.
And I gotta say, I thought the Stingray Special played great, too. I didn't detect an issue with that fret the tech took those couple of swipes with the fret file.