I thought about that and have been checking my b21 and L egacy for over a year with no sign of impact.
When I first started using them I used malleable buffer on the front bearing then realized there is no impact as the spring is not throwing the piston or bearing it it is pushing and if the pushing is done correctly there is an air buffer between the piston slamming into the receiver so there is no violent effect on the bearing
(If the gun is working correctly)

So I thought,,, what if the gun was not working as it was designed and do I really need the bearing in the front and the rear?
Hmmmm.
I removed the bearing from the front and ran the bearing in the rear of the spring the part of the spring that stays put with no banging it just kind of sits there twisting and grinding away with only lateral forces being applied,
This is when I realized!! That’s what the bearing was intended for even though I still use the bearings for the front of my Legacy spring and over a year its still smooth as silk with no signs on impact damage or ware.
So for the most part I would use the bearings on the rear of the spring only! As springs really only need one side of the spring to not stick, grind and to stop the twang from the sudden release of steel under torque.
But to get back the 350 it has 2 bearing races one on the top and one on the bottom of the spring if the gun is properly lubed the spring will not twist.
One thing to remember the RWS 350 is what the industry has determined is a true airgun magnum and no matter what field you’re in when the term magnum is used there will be a slight increase in difficulty of control give that bad boy some time let it break in and give your self some time as well to learn to control the beast.
I have 2 RWS 350M 177 & 22 I like them very much and it took some time and effort to learn to shoot them its big its bad and it like to kick but dead on accurate and powerful in the springer world.