Keep in mind there is a fundamental difference between the front level kits with OE coilovers and the air suspension.
On the coilovers most kits add a spacer between the shock and the frame effectively making the shock longer. The Bilstein mounts the seat of the spring higher, doing the same by lengthening the bottom of the shock below the spring. Travel and spring rate are unaltered.
With the air suspension, whether changing the length of the link between the sensor and the suspension or by changing the programming, the change is made by making the air spring stiffer so it deflects less. Not only does it make it stiffer, it also changes the ratio of bump travel to droop travel. This is why OR2 seems very stiff and the speed is very restricted. Raising the front or raising the front and lowering the rear will change the relative spring rates which can have an effect on the ride and handling.
Both change the geometry. FCA didn't publish specs for the 2019 Rebel. From the 2015 Rebel, the cab heights are the same as OR1 and OR2. Since it has a taller tire, it would mean the suspension geometry is different than the Off-Road Group at normal or the regular version at OR1.
Net, there is no free lunch and we don't know enough to tell what is good or bad. However, I probably wouldn't 'level' the air suspension and if I did not by much. For rock crawling a Gladiator Rubicon is a better choice; even a Raptor will scrape its exhaust and hitch. A 34" tall tire will fit the OE normal settings, although a 295/55-20, 305/55-20 or equivalents in 18" and 22" wheels may be better choices for the street.