Im using Protools 2022.12 "in rosetta" on a Mac Studio M1 Ultra. Mac OS Monterey and I have found a solid solution!
"V Control Pro" you can check it out here https://neyrinck.com/
This is an app that allows legacy equipment to work, via HUI, with any current release of ProTools. For example old C24 type boards, from the Digidesign days, can work with an hdx or carbon on any new Mac, intel or M1 or M2.
V Control Pro supports the Faderport with a custom map that "supercharges" it for ProTools. I figured the code for that application wouldn't be far off from the SL 32s iii, so I downloaded the free version to test out. The setup is not straight forward, but it is pretty well explained.
I found that the issue was that protools would receive communication from the SL32siii... BUT the SL32siii would not receive communication from ProTools, or any other HUI capable DAW or editing app.
V Control acts like an adapter to help ProTools and UC talk. In the initial setup of V control, just like in UC and ProTools, you have to check all four "banks" UCNET sl32 main and ext 1, ext 2....
In ProTools, in the "Midi Controllers" tab of "Peripherals," setup HUI to receive from ucnetmidiSL32main and ext 1,2,3. Then, setup HUI to send to V-Control and ext 1,2,3.
This has worked for me and I must say, it is even more solid than when I was working on my old Mac Pro using Mojave and Catalina. No warnings that Protools can't communicate with HUI... It just works, solid, every time I boot up. Still no Pan control... but everything else is there.
I am not affiliated with V-control. I simply discovered this and wanted to share. Maybe Presonus can get a copy and see what Neyrink did. This might save someone else the $200 I spent on a perpetual license to V-control Pro.