They should last more than rubber inherently because of the material but mostly because in the the case of the A-arms, the arms pivot from the mounts in those bushings up and down. the rubber bushings are fused to the sleeve and the housing so they're not designed to freely rotate per se so the bushings have to literally be forced to deflect up and down as the suspension moves which is why is supper important to preload them at ride height. they're not designed to take into consideration more shock travel so assuming a standard length strut and stock heigth the'll work well within their operating range. Top spacers forces them to flex more than normal.
Poly on the other side will rotate freely around their sleeves and depending on bushing design they can also rotate in the housing or around another layer outside the sleeve like many flex joints, Giiro DDB's in Claytons, and other flexy DDB's. We don't have that type in the front UCA's nor is needed. a normal free pivoting poly busing will work well cause all the a-arms do is go up and down as the coilovers cycle, so you don't even need to worry about tightening a little above ride height cause they literally free spin.. and they don't deflect side to side like rubber can so your suspension from the pivoting arms have literally no side to side movement which you want if you're playing in the dirt at speed. Zone are not exactly performance UCA's in that sense because their rubber bushings for the pivot points and standard bj's. Don't mean to say they're bad UCA's though. On the contrary they're more HD than the stockers, but if you are playing in the dirt and have extended travel suspension, poly busings with a bj than can flex more like Icon DJ, JBA BJ, any of the good brand uniballs etc not only will outlast Zone but will give you all these benefits pretty much in full. Yes a bit more maintenance but it really depends on your needs. I grease my Icons every 5k miles, have yet to hear a single little sqwueak from them and i felt the difference right away when i made the change from Zone to Icon on the street but more when pushing the truck in those Socal washboards we have around
If you wanted to try something a bit less pricey i think the JBA's are the ticket, but you still have to grease them. is not that bad though. At least with the JBA's you wouldn'tneed to loose and retorque your bolts from the UCA pivots like we have to do with Icon for example.