Are you looking to limit the speed and power of the system? Using PAS isn't going to do that.
Or are you looking for better control over the power and speed you have, while still being able to go the full speed, and using the full acceleration power? PAS, as a rule, doesn't provide that. You'd need to tune the controller using it's software and setup program to respond to your throttle the way you want it to.
Usually this is via USB-serial cable from a computer; some controllers have bluetooth and can be setup via mobile devices (but may not have all the same settings available as in the computer-based program...or may have more settings available via mobile than computer). (the same method is used to limit speed or power).
Also, I don't think any "sabvoton" (of which, based on ES posts over the years, there are more than one manufacturer that don't make the same actual products but use the same "brand name") has a PAS input, since the typical PAS input is just on/off, so all you get is either full power or no power, at whatever assist level you chose on the display.
THere *are* controllers with PAS systems that do provide variable assist, some of them via cadence and some via torque, but to get those you'd have to change to those controllers, all of which are lower power than what you have there.
To add PAS to any controller that you want, you can use Grin Tech's Cycle Analyst v3 (CAv3), which is how I control my SB Cruiser's 2WD motor system via cadence control.
https://ebikes.ca/product-info/grin-products/cycle-analyst-3.html
You can also limit power, speed, etc via the CA, if you like, and it can also monitor your battery usage, etc. (useful for troubleshooting).