Thanks to all of you for your replies.
Obviously, Abyss, Magnum, MDN Sidecar etc. save their activation state at another location than inside any of the files which are stored on the system during the initial installation process. Or rather, the plug-ins save / recall their license status at launch. But in which file?

I found logfiles which contain programming code in ~/Library/Application\ Support/Pulsar\ Modular/ - those were not erased by Wide Blue Sound's Plugin Uninstaller. Also, I checked the default AUpreset files in ~/Library/Audio/Presets/Pulsar\ Modular/ and compared them with earlier versions from time machine. They did not change. I deleted all of them now.

So it turns out, the big question here is: how to do a REAL COMPLETE uninstall of Pulsar Modular Plugins. I hope some of you have some more experiences in this (or a similar matter) and can give some advise.

Unfortunately, MORiA doesn't reply via PM on the sister side. And I don't know another way to get in touch.
So, every hint and support is very appreciated.
Thank you.

 

First part, as I said Wide Blue doesn't find "Everything", but it gets you way closer than just deleting plugins manually. I use this program called Dr. Buho Cleaner, and it is like CleanMyMac. I've never done a shootout between them. Those aren't even the only ones, and so it might come down to what you can find or what you want to "pay for". They do not just find everything and get rid of it; they can often easily get rid of "too much." So you have to be careful automatically cleaning. FAF is killer for it, and I still see stuff you can miss that way.

WideBlue does not do a Monitored Install method like Revo Uninstaller does; but it does find a lot more than most other quick options. It works best when the plugins are still installed.

Don't forget stupid plugin formats you might have installed. Look for the folders /Avid and /Digidesign. Also, look in your Documents folder. Don't forget the ~/User locations. You can often find presets in more locations than one, and that is often how shared plugins "don't have any presets". They just get stuck in the wrong location.

I never seem to have these reinstallation problems, but that is because my firewall works right And I still use more than "just Little Snitch" for dumb things like the Tahoe LS problem you seem to have had happen.

One last trick, Google Mothers Ruin Suspicious Package. It lets you look inside .pkg installer files (like Pacifist does, but it isn't annoying like Pacifist). Then you can look at the pre- and post- installation scripts and a directory tree structure of where your plugins put every file when you install something, before you install it. You do need the original installer to look at, and if you do not keep copies of installers you do have to download another copy of the installer. Then you can manually look and see everything Revo would by doing a Monitored Install.
Almost all plugin installers will be either .pkg files or .dmg files. With .dmg files, you have to first click the dmg like you are installing it to mount it as a virtual disk drive. Then the installer .pkg file will be the second install file you would normally click; sometimes with a nice custom background like HCiso, Moria, Guseppe all do. You can right click that file and open in Suspicious Package.

Make sure you have firewalled your DAW in Little Snitch. LuLu and Little Snitch can be overkill, but I can tell you they work perfectly together anyway. They can cause an issue with your Transmission torrent client, if you use that. But that is a bridge worth burning when you get to it.
You can always use Mac OS system firewall to block outbound data for applications like your DAW, but maybe not for plugins.

Anyway, tldr. Hopefully any of this will help you get more control of your Mac.

 

Could it be that the plug-in writes some hidden files on users hard drive when it realises it is not running a legit copy? Might be then tricky to get rid of it ... I remember I extended some early ilok plug-ins demo mode by deleting some hidden files it was writing (even on external hard drives) to check for the demo period. I used some program to track which files it was writing when running the plug-ins, those were the times heh.

 

The activation status gets presumably recalled from files which are created while running a Plugin inside the DAW. But I checked - there are no PM preference files to be found in both Libraries.
Wide Blue Sound Uninstaller unfortunately does not recognize and delete files which were created by any Audio apps or Plugins while being launched.
EasyFind didn't give me any helpful search results so far (hidden files, contents etc. included)
Any other knowledge about licence storage locations?