Talk about over thinking a simple problem [like much of YT these days] With the mass axle loads of a LR on any joint poly or rubber will make near no bloody difference as it's the material Shore Rating that's key. I do wish YT could pre-qualify people before they post their vids as once online the world takes it as gospel...and I won't comment on his grit paste [ever heard of jet washing out?] The real advantage of poly over rubber is 1. +Ve axle/joint location, and 2. longevity. Of course there's a slight increase in NVH that's negligible on our trusty tratters.
For technical ref' I SuperPro bushed my Subaru Forester XT some six years ago, every joint front and rear including sub-frames and diff mounts. To date not one creak or clonk and zero signs of wear...and Subaru's eat bushes like no tomorrow. The trick with poly bushes is absolute cleanliness at assembly and liberal use of bush lube/white grease...after all, a thoroughly lubed bush is what makes the world go round