I finished my integration work.

Mod_PCB_Integrated_PSS_A50_Small

Mod_PCB_Integrated_PSS_A50_Vertical_Small

The question we would like to know the answer : Will it work ?
The audio/video answer will be provided in a new Youtube video I'll prepare later.

The written answer is : "Yes, it works fine, as expected", with no reworking needed. Also, no additional noise (from ear, subjective, with headphones) compared to the genuine PSS-A50.
I'm really happy with the result and the nice integration.

1. I'll publish later an article with the details of this integration.
2. I'll also publish later another possible integration of this PCB, without (the complexity of) using 1.27mm headers, but (easier) just using wires instead.
3. I'll also publish later an article about audio noise when recording from the usual audio input of the PC, if the PSS-A50 is USB connected to your PC (sending midi to the PSS). Solution : use audio 1:1 transformers (usually 600 Ohms) in order to de-couple the ground

Please also have a look there (about my mod) : https://darekasan-net.hatenablog.co...
Or there (about a midi Bluetooth mod) : https://darekasan-net.hatenablog.co...
(Chrome can translate in case)