BlackMagic Design Desktop Video continues to be a pain with FCPX...

I'm at version 10.8.4 of the Desktop Video app by Blackmagic Design, the "driver" app that allows your favorite NLE to output video to an external monitor, and it's still incredibly unstable with FCPX (now at version 10.3.2.) Like I turn A/V Output on in FCPX, and 30sec. later... CRASH!

What game are you guys playing Apple and BMD? I know that Apple allows to output video directly from Thunderbolt, yet I don't have that luxury, I use video cards. Aja does not have that instability.

I am now a year later, two major OS X upgrades, and two major FCPX upgrades from when I first posted this problem, and I'm on a different machine!

Why is it still unstable. Why?

Users have to go back to version 10.4.1 of the app (released June 10 2015!) to have some stability:

FCPX Crashing w/Desktop Video + Ultra studio Mini

Really? Well thank you for making it available, but one would thing that after three full versions releases you would have fixed this pesky Desktop Video problem, why do you not care BMD?

Blackmagic Design Desktop Video 10.5.4 on Mac OSX 10.10.5 keeps crashing FCPX 10.2.2

It's becoming annoying, BMD Desktop Video 10.5.4 crashes FCPX at every occasion - like dragging a clip across the Timeline.

I've had it, I've retrograded to 10.5.3, and the rest of the day has been fine, no crash.

I was on Desktop Video 10.5 before and it was stable. This machine has a DeckLink Mini Monitor PCie.  I will stay on 10.5.3 and wait for the next iteration after 4.
I'm not alone: http://forum.blackmagicdesign.com/viewtopic.php?f=3&t=44128

--- Update
DV 10.5.3 is also unstable, although less than 4.  I'm back to 10.5.

--- Update
DV 10.5 is working fine, no crash so far.

What is your experience with 10.5.4? Stable? Unstable?