This hasn't been documented (and I haven't tested), but I'm fairly certain that on user level you can't block your comments and posts from getting federated with other instances. That would be instance-admin level settings.
The federation on/off button should only hide federated content from you, but I'm not sure if it even applies to the stuff that has already been loaded into your feed, as I still see some content from other instances if I turn it off, but could be due to other kbin users who have commented on the thread so you'd only see kbin users comments.
Still waiting for bit more documentation on kbin, but I'm sure a lot of it will change as ernest and other contributors work on the code.
There used to be direct links on plcman forums (.co.uk) but I believe they stopped maintaining the forums and none of the links work anymore. Sadly I haven't been able to successfully find any cracks / cracked licenses for PLC software in a long time and don't work in the automation industry anymore.
If you are working in an automation company, for siemens software you can still pretty much do the old: install on a virtual machine, move licenses, shutdown virtual machine, copy paste virtual machine -routine since the license manager still doesn't connect to any online sources to check.