Hi @N0_Klu3 - I also use an EyeTV Netstream 4Sat with Plex and run PMS on a Mac mini.
Assuming you don’t have any Sky subscription you should tune into Freesat South using your settings, i.e. 28.2E, None, Ku-Linear (Universal).
But you will notice a lot of issues particularly with the Plex EPG - this has nothing to do with your setup but you will find that many programmes don’t show up in the EPG, are wrongly labelled, don’t get recorded, etc.
Have a look at New Plex Guide Very Poor in UK