That all sounds positive, I believe oil resistance is a clear gain for PU? Some of the cars you mention probably have short suspension travel, which will reduce the tendency to squeak. I think that makes the Jaguar vulnerable as it has relatively long travel.
A possible approach would be fitting a stiff PU bush in the lower control arm front location only. As described in the link below, my simulations suggest that would give the major gains in response and lateral stiffness because that bushing takes by far the major part of cornering / steering load. (By geometry the upper bushings take little load, and the front leg of the lower arm is directly in line to handle cornering loads coming in from the lower ball joint).
That should make the response feel more “crisp” while retaining the bump absorption and damping properties of the rubber rear bushing and cutting the number of potential squeak sources.
As a caution for future discussion, compressibility is usually defined as the ability to be compressed, that is the inverse of “force you need to compress the thing” which is stiffness! Sorry to be pedantic but we might not want this to get more complex than absolutely necessary 