If your phone is plugged into your Jeep and using CarPlay/Android Auto, it won't show phone GPS speed, it'll show speed reading that the Jeep is sending to it.
I could tell a distinct difference when reprogramming for my change to just 285/70R17, so I can't imagine you wouldn't need to do yours.
I think he understood; he's answering your question. If you want the halos and DRL's to work, the new Jeep will need a wiring harness. He's suggesting that instead of doing all the work twice and having to source that harness, just leave the originals on your old Jeep and get the complete Mopar...
It is possible to do it without loosening the control arm bolts, but you shouldn't.
Not knowing any better, I initially did mine without loosening the control arm bolts, and I had to get a bigass pry bar to get the rear springs in. I only got like 1/2" of height.
I re-did it by loosening all...
Ain't no loophole. Jeep is up front about it. The presence of aftermarket parts and modifications is serving a warranty denial opportunity to them on a silver platter.
Should be fine. The weirdness is that Jeep uses a pissload of different springs (i.e.: not all Rubicons have the exact same springs at all four corners). That said, any set of Rubicon springs should raise your Sport at least 3/4" but probably no more than 1.25".
Gas Rubicon springs/shocks...
I agree. Same thing as full-size trucks. Be it Ford, Chevy, or Ram, their max tow possible is always some weird configuration no one ever buys anyway. Buyers of the Raptor/Trail Boss/Rebel know they're not getting that maximum tow rating.