I understand when one removes a 'soft-mount' from moving suspension parts and replace them for 'solid hardware' then roadnoise will be carried further into the body structure.

But will it be something like running with solid engine mounts, or much less and more like a slight noticable humming noise? All the time or just more when braking?

Maybe one way to check how much noise is really "inside" the strutrod during driving, it would be a fun idea to mount some kind of stethoscope on the strutrod and extended to the inside.
But I'm sure someone already has first hand knowledge of these things.