I have oak 22mm with tough water based varnish amazed how durable.
Do not turn orange.

Family member had overlays and they have been fine for several years.

I've made and fitted lots of worktops in the past, of all descriptions, 'but not the newer overlays. I see no reason why they shouldn't work well, but the devil is as always in the detailing, to achieve a clean crisp finish.
Before committing, esp if there are awkward kitchen layouts to consider I'd want to know about, templating, how do the fitters do that, wall upstand detail? new cabinet overhang detail? sink overhang detail? any joins and method used, Is the material only available in straight lengths? How do they deal with uneven walls plus existing cabinet ability to take extra weight, legs etc..

P.S. You've most likely researched it already , but there are lots of different man made worktop materials, some more "resiny" than others and with "more or less" natural stone in the mix, or synthetic coloured additives each their own durability and aesthetic.