Technical explanation of the Monroe Sensa-Trac shock
To answer your question regarding tire interference, you need to limit your suspn travel during bump (compression). Not certain you can achieve that with firmer shock valving. It will help, just not certain. One method may be to place rubber bumpers on the shock's piston rod as this will limit the amount of bump travel. Or add firmer springs, which will change your vehicle's handing dynamics as well.
The Monroe Sensa-Trac shock (or strut) was designed to allow for improved comfort under normal driving conditions. "Normal" meaning the small range the suspn and shock absorber travels during non aggressive driving conditions, such as on the interstate or around town. Firm shock damping is not required under these conditions.
Once the shock absorber traveled outside of that range due to hard cornering or going over a large bump or pot hole or even hard braking, the shock valving in both compression and rebound becomes significantly firmer where it is needed.
The Sensa-Trac design works this way because Monroe fabricates the pressure tube with a couple of grooves running longitudinally at a designed controlled length.....above and below the normal ride height piston position. These grooves allows for shock oil to pass or "leak" by the piston band creating a softer ride. Once the piston moves above (during extreme rebound) or below (during extreme compression) the grooves, shock oil can no longer pass by the piston band. At this point, the shock oil can only flow through the normal shock valving (piston bleeds, orifices and base valve) whick is considerably more restrictive yielding much firmer damping where it is required.
It's quite a nice design and was developed back in the late 90's if I remember correctly. But it was designed to improve ride quality during normal suspn travel, not reduce maximum suspn travel during bump or rebound.