Value of "GetForceCamera" hook could possibly overwrite your custom mode, and if set to "CAMERA_MODE_SPEC_ONLY_FIRST_PERSON" (2) eye camera will be set internally.

Hi it seems in my server spectator restrictions work fine. Also i think if you have problems then you can set GetForceCamera return to any values? Sorry if my anwser is irrelevant, i dont understand much.

This can be pushed too (with adjustements regarding other hooks of @fl0werD, or keep v5.21 and merge all [4 hooks] at once).

I was just refering to the "5.21" version upgrade, but I think while the maintainer/collaborators do not push a release in the "Releases" section but keep adding/merging some new API functions, your hook could keep "5.21" as version and be added after fl0werD's hooks recently added (other API functions could even be added at same time and keep same version), no need to push to 5.22.
But you probably have to edit "the conflicts files" listed below.