There is no option for companions. The game seems to randomly decide to kill them for whatever reason, especially if you just sit and don't take part in the mission and actively go kill people and etc.
Occasionally I did see a mouse cursor. I am working on the game and playing it in windowed mode. Perhaps it's only an occurence when the game isn't fullscreen.
I am using the EPIC version which both versions launch with Rockstar.
I set up my game settings once I was already in the game doing this:
Once you load into STORY, and can move your character, press ESC.
select settings, graphics, then:
Screen Type Windowed, then modify your Resolution accordingly.
Once that is done, I ran trainer, press F1 while already in the game.
Says activated here. Options in trainer can also be activated using your mouse and clicking the option buttons in the trainer.
Works here no issues.
This game does all manner of manipulation of api calls and input capture manipulation I guess to increase the optimization of the game. Perhaps for some players and their hardware it is not allowing keys to be captured by outside apps if you are IN the game or in fullscreen, etc.
Not sure what else to say. We aren't doing anything different or strange with this game and our trainer app has worked flawlessly for 100's of games the last several months.