On my knownledge it surely is safe to inject as long as csgo is not warning you about that. As the update log say
"
CS:GO now significantly restricts the types of programs and files that can interact with the game.
In the unlikely event that you launch the game with incompatible files, you will receive a warning indicating the incompatible file and may be blocked from joining VAC-enabled servers. To resolve the issue, you can disable the ‘Trusted Launch’ in your game settings, however this may temporarily impact your trust score.
"
So basicly possible impacting your trust core, but certain that It will work without getting vaced probably. Cannot promise anything, If you really want to be safe I would instruct you to just not use it at all.
