You need to get rid of the thoughts between your ears.
Start with the the knowledge and fact that you are running an LPT engine using RON 95 fuel. This is already a lose-lose situation. It won't become a T5 ever.
Practise shows that on average the older LPT's don't like boost beyond 15 psi, preferable 13 psi.
The LPT's already come with the different ignition map so try to find an LPT image and see what timing is used.
Also flatten the timing also in the cell before where the knock occurs.