Short answer: it is possible, notify the devs.
Long answer: since Toribash Next is being made in Unity, it is simple to implement a specific frame rate cap in the engine, as well as adding a number box as a target in the options menu.
The example above uses C# to control and view the frame rate in real time, which is the same language they are using to code the game with.
Suggest this idea in the S&I board, and it might be implemented, the game is still being made so it should not be hard to do so.