My main Q was about dynamic headroom if I crank the linestage up. Per Al, shouldn't be a problem. If it is, it's likely happening on classical records which generally present large dynamic swings in volume. Less so on compressed rock
How you word your question suggests that you are thinking in terms of how an amplifier is set up. Specifically amps are almost always set up to achieve full output before you run out of volume control, anything farther causes overload/distortion. Preamps on the other hand are typically set so that as long as you do not overload the input you will not reach full output (before overload/distortion) even with the volume control all the way up.
IOW, in properly set up preamp/amp set up you never drive the preamp into overload and distortion no matter how much you open up the volume control. The overload is in the amp.
This is why the other posts are discussing noise levels/issues as that is the major concern when having to turn the volume control up all or nearly all of the way.
HTH