Fantastic, the script works after running on the platform (ASRock J-3455 ds918 6.23 up3). Here's the runtime prompt, I did patch for all the files, right?
root@XXX:/volume1/music# ./patch.sh -p
Detected DSM version: 6.2.3 25426-3
Patch for DSM Version (6.2.3 25426-3) AVAILABLE!
Available binaries to patch/restore:
1) /usr/syno/bin/synocodectool
2) /volume1/@appstore/VideoStation/bin/synocodectool
3) /volume1/@appstore/MediaServer/bin//synocodectool
4) Quit
Please choose which binary you want to patch/restore:1
Detected valid synocodectool. Creating backup..
Patching...
Patched
Creating spoofed activation.conf..
Spoofed activation.conf created successfully
root@XXX:/volume1/music# cat /usr/syno/etc/codec/activation.conf
{"success":true,"activated_codec":["hevc_dec","ac3_dec","h264_dec","h264_enc","aac_dec","aac_enc","mpeg4part2_dec","vc1_dec","vc1_enc"],"token":"123456789987654abc"}