At long last I installed my rear spacers on my 2016 Trail yesterday.I had had them for several months and wanted to live with just the front end raised using adjustable Billstiens set at 1.75.It was a very easy process with just my son and I and done in the driveway and took 2 hours.I did not use spring compressors.Having "popped out" both shocks and disconnected the sway bar I put the jack under the axel by the shock connection and raised the axel on that side which lowered the axel on the opposite side allowing me to get the spring(coil) out.The spacer was put on top and coil re-inserted and "seated" correctly.Same for the other side although you need to raise the axel higher to compensate for the installed spacer.
It was much easier than I imagined!

Let’s see it

Yep, in my experience, the rears are super simple on anything from a T4R to any model SRA Jeep to even a QX56/Armada. Actually I think the QX rear with its IFS was the easiest spring swap I ever did, that's surprising. Unbolt like one bolt and let jack pressure off and they fall out. You don't even have to touch the shocks. I think it was an hour or so taking my time.

The fronts however, are always much more of a pain, even on a vehicle like a Jeep that doesn't have struts as the QX or the T4R does. It's just always more involved and the springs typically droop more too so it's harder to free them.

I've done lifts and lowering kits on dozens of the the above and also on Subarus with struts. Nothing took me as long in the front as the T4R did nor was I as sore at the end. Either I am getting old or I tried to do it the easy way which actually ended up taking longer. Might be a little of both.

Haven't touched the T4R rear yet but I would certainly expect it to be a cakewalk as you describe.