Yeah, this is why many luthiers making marked necks are more and more using smaller 'side lines' or dot patterns:
View attachment 4282535
In my case, it was due to my Combustion being a conversion. I had an unused 'spare' and wanted to get back into fretless but didn't want to drop $5K+ to test the fanned fretless waters. Of course, in a way that only I can do it...I turned a bass that cost me $900 into a $3000 project.
I've now had mine for a couple years, and the neck has done admirably through very humid summers and very dry winters. I find that neck relief with fretless is super important and also tweaky because I like my basses set up as low as they can go, and when you're on that 'edge' a tiny little neck bow forward or back can make your bass either uncomfortable or unplayable.
Though, to get the the point of all that Luminlay wasn't easy and there's more to it than just the inlay material. The bass was first converted by a professional (ah, hrrrm) here in the region (someone who mostly does orchestral strings)...and it was not a great job. I couldn't get the action where I wanted it (both in correct true-ness but also because he refused to shim and the bridge was bottomed out). The inlay he worked with was boxwood...and it DID 'breathe'...To the point where some inlays expanded and at least one came unglued. After him taking a shot at re-fixing it correctly, I cut my losses. I'm also not sure that he did the discussed fretboard coating which would have been a HUGE help, and was the professional advice of Sheldon Dingwall, who I consulted with before the project.
...the bass went to one of the best. I shipped it to Maurilio Mina in California for a total neck re-do. He cut and drilled out all the lines and markers and did it right. Properly trued, the whole neck was re-finished in a very hard satin poly (and is one of the best feeling necks I've ever had) that seals the fretboard and also keeps the neck from being to humidity sensitive. The issue with the bridge was not only addressed but we also added a customized piezo setup, a second preamp and electronics to be able to use both or either, and adjust both magentic pickups and piezo effectively.