3.1 unstable on Yosemite
 

I am sorry to report that 3.1 is unstable on Yosemite (10.10.5). It repeatedly crashes while working with Omnigraffle (just scrolling) and this was perfectly fine on 3.0. Reverted now. When it crashes it logs out all users of the machine (not just the active one) and goes back to login screen.
I have a 20" cinema display on displaylink as primary screen and a 1024x768 dummy screen running on an ipad with Duet as the secondary.

Hi dazey,

We tested this use case and found no new instability on two systems. I fear that you are seeing a known instability in Yosemite and El Capitan where the Window Server would randomly crash because of timing issues.
Depending on the system a different driver version and introduce or resolve these issues.

Even a reinstall of either the driver or the OS can sometimes change some of these timings.

Sierra is much more resilient to these issues, you may consider upgrading. Or keep 3.0 in the meanwhile if it is working well for you!

Best regards,
Carlo