It really depends on what you’re trying to patch. The Dual Rectifier’s half wave rectified outputs (Top/Bottom) are extremely useful for splitting one 0-1V signal into patchable segments. It basically splits your input signal into two segments, below and above 0.5V but adjusts them back to 0-1V range on the outputs. Two Dual Rectifiers gives you 4 rectifier stages which means you can easily split one modulation signal into 4 even segments or more with a little attenuation that can be distributed across multiple modules. I blather on about that here where we talk about how to patch animation timelines.
Two Dual Rectifiers also gives you 4 stages of full wave rectification which can give you a very dense solarization effect. If Staircase is your jam and you want to be able to have a more ‘fixed’ patch programmed version of it, this is the way to go. If you want it to be animated somewhat similarly to Staircase, just run your original signal into a VCA before putting it into the first Dual Rectifier. The first Fold output is normalled to the second input so it just takes one patch cable to have 4 stages available on the output.
I think @jwsmithwick1’s suggestion of hooking your Cadet ramps right up to a GAMMA is a good idea if you are primarily working with shape generation. You’d want to use the inverted triangle ramps if you are after circle/pincushion shapes on the bottom two outputs. It might be a little redundant plugging it into Diver since you already have expo/log ramp waveforms available as two separate banks. Putting an exponential signal into an expo converter just makes the curve that much more dramatic so it’s still useful for experimenting with.
The Gamma control on Shapechanger is effectively the two bottom outputs of the Gamma module routed into a fader so you can go Log<->Lin<->Expo or Circle<->Diamond<->Pincushion Star.
In the context of your system, I’d personally add a 3rd VEIL so you can stack 3 RGB layers. LUMA/RGB2YRGB would also be a handy one so you can pull a key source related to any arbitrary RGB pattern in your system, not just from Memory Palace, TBC2 or Chromagnon. I often take that the Y from that module, key it, and then put it into the CV input of BSO Crossfade to get deep blacks around RGB patterns that exactly matches their shape. Your RGB pattern would first go into LUMA → one side of BSO Crossfade so it requires minimal multing to patch.
That rack seems like a ton of fun already!