I have to say that that is a downside of Easy Installer. It is described as Beta, and I suggest it is easy to use when you know where you are going. In general it should cope with a few unexpected circumstances, but it might not.
If you are saying that you have very little experience and you want a learning experience it may not be your best fit with a valuable phone.
You might like to find a junk shop phone and experiment with lower risks, the reading you will then have done should allow you to make the judgement on your S9 without anxiety.
Bon chance 
… Oh and you might search for Bluetooth issues here, and check if it affects that device, it is being worked on!