I still mtb and have a Cotic Jeht and a Spec Enduro. I find that these remove all the trail buzz and allow me to ride and even jump without any effect on me.
I’d maybe just ride those for a bit, maybe stick some fast tyres on the Jeht to make it more tolerable on the road, and see if things calm down over time. I think the whole staccato thing goes with the gravel experience tbh, even big gravel tyres can only manage so much, though a mate who runs a Rockshox Rudy on a Stigmata says it makes an appreciable difference.
I made the basic error of riding my Camino with 45mm tyres across the Pennine Way track from Snake Summit to Mill Hill the other day, it’s paved with old mill slabs and it was an absolutely horrendous experience, constant jolting from the slab joins mixed with micro-crap from the texture of the slabs, worst route-selection error I’ve made in ages. Gel pads under Supacaz bar-tape fwiw, non-extreme riding position etc, it is just how it is. The downhill afterwards, also on slabs, was even worse.
The same track is fine on a mountain bike. I think essentially it comes down mostly to tyre volume. You can ride as loose as you want, in or out of the saddle, fast or slow, and it’s still horrible, just at a different frequency. I’m sure you can mitigate it somewhat with component choices etc, but them’s the basics.
Also, I guess you’re descending on the drops, so the angle of your head / neck will have changed compared to riding on the tops/hoods, I guess it might be worth experimenting with set-up to see if you can mitigate that. Something like a Specialized Hover bar with flare which raises the whole bar might possibly help? Looks ‘interesting’ but if it works, it works.
