GitLab API - update issue notes with system flag set to true?

Hello, another question I have is if I can set the “system” flag to true from GitLab API. The documentation (https://docs.gitlab.com/ce/api/notes.html#modify-existing-issue-note) indicates this is not possible and when I did try it out indeed it did not work.

So I was wondering; is there any other way how this can be achieved?

Given I am extracting issue notes from an old system I know which of these issues are system generated and which not (through the same issue flag). However it seems there is no way for me to indicate to the new system that a specific issue note is/was system generated.