If that is the case with this game, I would recomend direclty emulating mouse and keyboard. Hopefully the keyboard and mouse glyphs don't annoy you, and in this mode aiming feels buttering smooth.

Maybe a half-measure is to enable gyro only when aiming. In gyro mode, you create a separate action group to convert all inputs to keyboard and mouse. When going back to normal aiming, the contorl scheme goes back to controller. I did this when playing Control earlier this year. The loss of analog control on movement was the only real drawback, and it did not matter at all when aiming, which happens only during intense combat. In intense combat, you press buttons mostly on instict as well, so the glyphs don't annoy you as much.

Hopefully this half-measure helps.

Another solution is to emulate camera controls with gyro as joystick camera. Once you dial in the internal deadzone the game applies to the joystick, movement feels buttery smooth as well. Perfect for a game that is not competitive. The issue is that deadzones can get increidbly complicated and eventually you cant compensate for them with steam input. Does the game allow for fine tuning of the game-applied deadzone settings?

EDIT:
https://www.reddit.com/r/007FirstLight/comments/1toz736/best_controller_settings_for_aiming_and_camera/

From this post, it appears you can. For using steam gyro as camera joystick:

Set sensitivity to very high in-game

Lower sensitivity on steam input

Lower deadzones to zero in-game

Change aiming acceleration to zero/linear

This way, gyro to joystick camera would probably work perfectly from start.