That reply is concerning... I'm on a 2018 MacBook Pro, maxed out specs for the year/model, running Catalina. No reason from a hardware-perspective this should be happening. The Windows laptop is a little older, but running the latest Windows 10 and plenty of horsepower. Also the way this performance degradation manifests- slowly while using the app getting worse and worse over time, looks much more like a memory leak in the software (either the Editor or the pedal itself) rather than "computer is old." I'll definitely be pressing the issue with SA if I get the same response.
To be fair, they specified that my OS was old. I'm on OSX 10.10.5. But since you are having the same exact issue, there might be a different reason?