I repaired my rear transmission mount and axle pivots with pourable polyurethane. I think it would be possible to replace the rubber portion of the front engine mount if a proper mold could be made. It would still be kind of fiddly with the multiple components. The availability of relatively cheap replacement rubber parts with the steel sleeves makes it easy to fix if vibrations become an issue.
But I agree with you that it's not the best design.
