This is quite a common upgrade for Jeeps and a highly recommended one. Quite ironically, Trading Enterprises themselves have recommended it 😂.
If you have a Rubicon, it would have Dana 44s, both front and back, which are much stronger and beefier axles, so reinforcement wont really be necessary, unless you really push the car to its limit.
But for other Trims, they have Dana 30s in front and 35s in the back, which are relatively thinner and weaker. And reinforcement is highly recommended. Though I believe you can easily go Fewbie+, as the drives aren’t that intense….. yet.
Reinforcement is also recommended if you upgrade to bigger tyres, or do High speed driving involving a lot of bumps. As it helps to support some of that sheer weight on the Axle.
For my car, ‘09 JK, I have Dana 30 in front and Dana 44 at the back, hence why I have only reinforced the front axle. I did it for the peace of mind, as I have heard of and seen several broken axles for Jeeps, but now I do have a lot more truss-t (pun intended) in my axles.
So I say, up to Fewbies, you don't really need it. Beyond that, it isn't required aswell if you drive safely. But perhaps you should consider, atleast for the front axle, once you reach Intermediates. Not necessary, but rather a safety precaution, cuz a broken axle in the middle of the desert wont be good, i think…