Jack here, again.
Okay folks, here's the deal.
Our new streamlining of the YYC-compiled build has revealed some critical flaws in our framework. If you are running the YYC (higher fps build from the experimental branch) build, you will be unable to rebind the mouse buttons to game keys.
However, you should be free to do this in the non-YYC build, which is the default branch.
Once the YoYo devs resolve this issue, we will move the YYC build back to default branch.
Until then, if you'd like to subscribe to the YYC build branch, simply right click on miniLAW in your steam library and check out the "betas" tab in the properties menu, like so:
Thanks for hanging with us during this strange issue, and we really appreciate the feedback and activity on the steam community hub and all our social media platforms.