Michael, I just did my test flight from KJAX to KMIA under these conditions.  First I did not touch the payload of my 57, because it is perfect as is.
When I did my preflight in the FMC, I keyed in a CG of 39%
Then I pulled my genuine flight manual to set my stab trim,
at my weight of 160.0 , 39% CG is 2.0. I set it for 25% - roughly where I fly.   at 3.5.  The take off was normal at V2.

In flight my angle of attack was normal- under 2 deg.

I landed on RW 9, in a light crosswing. Vref30 was 118kts. I added 2kts for Vref30  120.

Over the treshold, 2 deg of nose up.  After touch down, a good delay of 3 sec and the nose wheel was lightly down. Like it is always.

The 39% does not do anything except to show the aircraft pop up with a rear CG. The 57 flies with the weight & balance of the aircraft.cfg.
not with the FMC number.

If the 39 was active , my airplane would have taken off at 100kts with a stab trim at 3.5 instead of the required 2.0 at a 39% CG<

It is a game Michael, not RW, but honest CS does a great job.
This little flight now. Real weather. some IFR patches, Miami open but clouds over me. A little turbulence close to the clouds.  Pretty good.
To get the weather, I look out my windows!   :)

Raymond    Boeing or nothing
KFLL   South Florida