Adding encoder settings ("SEI"s) into hevc Bitstream without re-encoding

[PengTang]

Hi,
I am looking for a possibility to add certain information (here "writing library" as well as "Encoding settings") into the hevc Bitstream after encoding so that mediainfo is able to present it an appropriate way.

Background:
I only found very sparse information regarding this concern on the internet, but almost everything in the opposite direction: how to remove thus information.
(E.g., even it is closed bc of violation of rules by the OP:
https://forum.videohelp.com/threads/394432-Metadata-Editing-%28Protect-or-modify-information%29)

I am not interested in this. My concern is how to add such information. For example I want to make my settings public etc.

What I did but with little or no success was to open the file in a Hexeditor and tried to add some lines. But of course, it failed.
I certainly could just re-encode the whole thing but I hope that there might be a more time and energy saving way.

As I noticed in the abovementioned (closed) thread, please apologize if my concern does not make any sense in your opinion.
I want to understand and learn how to find a (more or less) satisfying solution. I should further mention that I do not have well programming skills, unfortunately. However, I would be grateful if someone can assist me

EDIT:
currently, my encode looks like this:

Video ID : 1
Format: HEVC
Format/Info: High EfficiencyVideo Coding Format
profile : Main@L4@Main
Codec ID : hev1
...

Assuming that I want to add my encoder settings etc, the following should be result some like (without re-encoding);

Video ID : 1
Format: HEVC
Format/Info: High EfficiencyVideo Coding Format
profile : Main@L4@Main
Codec ID : hev1
...
Writing library : x265 2.6:[Linux][GCC 7.2.0][64 bit] 8bit+10bit+12bit
...