I have looked at the original and two hybrids/mutants of the original design. (Sorry if I may be merging a couple of threads in this post.)
In advance- I am not trying to crap on any of the builds. There is just some confusion in another thread about whether the controller has to be spliced into the original thermo wiring, or if a plug-in receptacle style controller can be used.
Why does the original thermostat have to be tampered with at all?
As I see it, the thermo retrofit is equivalent to maxing out the OEM thermo (or various other tricks) to force an "always on" state, and then powering the original plug using the controller. If you still wanted the controller through-mounted for the bling factor, you could still do it, although bringing the original plug wires in from the outside may (or may not) be easier than accessing the OEM thermo wires. However, wires equivalent to the plug wires are also available at the OEM thermo, and could be wired to a plug.
This would simplify things for many, especially those who have different fridges; can't find/read their schematic; or don't feel comfortable messing with the guts of the fridge. It would be the mythical Unified Theory. It would also allow easier re-purposing of the controller, either temporarily or permanently. You don't even have to lose the bling factor if it is through-mounted.
The fridge with the auto-damper control is a little trickier, but can still be done with a plug in style controller. The wires to power the damper and fan just need to be wired to a plug, and plugged in to the controller. These auto-controlled damper fridges are functionally equivalent to the builds using a computer fan to move freezer air to the fridge side as a means of controlling the temp on the fridge side. The downside, which has been discovered, is the OEM fan/damper does not have enough flow for some situations. It was designed to maintain ~37F on the fridge side, but to do so with ~0F air on the freezer side.
Regarding the defrost control. The defrost control randomly disables cooling; adds heat, and is not a desirable feature for the control of serving/ferm temps. The defrost circuit can be eliminated, but a small fan to continuously blow on the coils would be needed. This is especially true if it is used for cold crashing, or maintaining lager/serving temps on both sides. A side benefit is the small fan would help eliminate temp variations as well as a number of other issues. In humid climates, there may still be icing issues. If you have icing issues and really dislike the "dumb" defrost cycle, there are controllers with "smart" defrost that only turn on when ice is present on the coils, and also have a "postpone defrost temporarily" function.