Hi,
Rather than trying to add extra functionality to the mouse inputs in Max, you could always try to configure your extra mouse buttons to send out keystrokes. This way you can perhaps get Max to interpert your button presses as Hotkey assignments through the Hotkey Editor in Max.
https://www.highrez.co.uk/downloads/xmousebuttoncontrol.htm
(One function is to "Send any keys using the 'simulated keystrokes' editor")
All of this working depends on whether your mouse, sans dedicated driver, can be understood by Windows in the first place. You may have to install the bloatware that comes with the mouse, and just try to disable the system utils you don't need. But, I'd give it a try with xmousebuttoncontrol on its own first, before installing any additional drivers. You can test Windows ability to read your mouse buttons here:
https://www.onlinemictest.com/mouse-test/
I just tested it out with my Logitech MX Vertical thumb buttons and it works with 3DSMax 2022.
All I did was open xmousebuttoncontrol, clicked the thumb buttons, looked where they were in the list (the dropdown item flashes yellow to indicate), configured the keystokes to output, pressed apply and then closed xmousebuttoncontrol. The cool thing is that it doesn't need to run in the background, underneath Max. It seems to just overwrite the default Windows interpretations of the button presses.
I downloaded the 'Portable' version so as not to have to install anything.
And then ran the 64bit exe inside the folder.
Hopefully this helps you out,
Regards,
Darawork
AutoDesk User
Windows 11, 3DS Max 2026, Revit 2026, AutoCad 2026, Dell Precision 7875 nVidia - Quadro RTX4000 ATA - AMD Ryzen Threadripper PRO 7965WX 24-Cores - 128GB RAM