Monster Hunter Stories 2: Wings of Ruin is now available on Steam as we expect. however, there are some issues & bugs with the new game. if you are suffering the frame stutters in the game. here are some methods for you to fix these issues.
How to Fix Frame Stutters
Turn on Steam input (right click on the game in the library list -> properties -> controller -> enable Steam input).
This issue may be caused by DS4Windows. just try to close DS4Windows. that will fix your issue.
More Method Will Be Added
Note: as the game is just released today. we will add more methods to fix this issue. if you have any other good methods. please leave a comment and let me know. we will add it with your credit.