Rear articulation limited by twist of leaf springs. Do aftermarket springs twist more or less?

I am trying to figure out articulation numbers for my 3rd gen TRD off-road DCLB. After detaching the bottom bolt on my stock shocks I jacked up the rear corner by the frame until a wheel lifted off the ground. It drooped to 23 3/8" from bottom of top shock hardware to axle shock mount bolt center. This is roughly 5/8" an inch beyond the travel of the stock TRD OR shock. I left this side lifted by the frame and started to jack up the other side by the axle. As I lifter the axle on the other side the axle quickly lifted back up to the end of the shock. So it seems that when crawling the stock shocks wouldn't really end up limiting articulation at all because the maximum angle of the axle in relation to the frame is limited by the twist of the leaf springs.

Do the various aftermarket springs available twist more or less than stock? It seems like this is a big part of how much articulation is possible in the rear.

Just for reference on my 2022 DCLB TRD Off-Road I measured an extended shock length of 22 13/16" from bottom of shock hardware to center of eye which seems to match the extended length of 5100s perfectly. Havn't had a chance to measure the compressed length yet or figure out the minimum used shock length at full stuff.

Also while jacking by the rear frame the frame of the truck was obviously twisting a lot.

 

If you're checking articulation, what you really should do is lift up the corner of the truck by the tire. Jacking it from the frame does not put the same twisting forces on the suspension as lifting from the tire will.
Quickest/easiest way to do this is if you have a forklift (or a friend with one).
An alternative is to drive one tire up some sort of ramp or incline until you can get one tire to lift up off the ground (driving at very low speed with the rear shocks removed won't hurt anything).
You should find the axle droops well beyond your stock shock lengths this way (and so yes, they will be a limiting factor). Be aware of your rear brake hoses while doing this, you don't want to over-stretch them.

 

Was just doing a quick test with tools at hand but didn't seem like the forces at play were that off from what a crossaxle situation would create. Definitely plan on doing more testing. I really need to get some ramps.

That said my current plan is to add 1" OEM lift blocks and switch to bilstein 5125 shocks. It seems that they perfectly cover the range of this setup and will allow for that extra 5/8" of droop without limiting up travel. A spring upgrade might be in my future but not looking to lift more than an inch and short on funds at the moment so it seems like a good upgrade.

 

Stock OR rear shocks are same ext length as rear Bilstein 5100s. I never tried a side by side compressed test but I figured the bump stop would halt any small difference.