Stereo Tool

Hi to all you Stereo Tool fans!

I am using Stereo Tool for about a while now and I like it very much. I'm still tweaking and tweaking to get to the sound I want and Stereo Tool is terrific for nerds like me.
Anyway, last week I bought a 2015 Macbook Pro and I migrated all apps from my 2012 Macbook Pro to this new one.
Almost everything worked fine, except I noticed Stereo Tool stuttering when it isn't able to display its meters.
So when I minimize the app or I resize the window to exclude the meters or the screensaver kicks in Stereo Tool starts stuttering after about a minute.

It's not immediately so it seems it's some sort of overflowing of some buffer-like thing.
As soon as I make the meters appear again all is fine.

Anyone perhaps any idea what could be going on?

Specs:
2015 Macbook Pro Retina 15 inch AMD 16 GB RAM 512GB SSD
OSX El Capitan
Stereo Tool 7.84 standalone Mac version

Audio routing:
Music App > Soundflower64 > Jackpilot > Stereo Tool > Jackpilot > Soundflower64 > Audio Hijack Pro to the output.

I also have a MacBook Pro, mine's a little older, a mid 2012. However, I'm trying to get Stereotool to work as a plugin for Audition. It works, but stutters like crazy, worse with more meters displayed. It will render it's effect fine, but setting it up with all that stuttering is impossible. I'm just trying to use the declipper and restoration.

15" MBP, 2012, OSX 10.8.5, 16gB ram, and the OS on an SSD.

Just confirmed, stuttering is directly related to the display. The more going on on-screen, the worse it gets.