Hi @lamsey, the patch fails because I had originally written the patch for Ubuntu 18.04. The patch attempts to install an older version of librealsense2, however, this old version number varies slightly between 18.04 and 20.04. Since those packages don’t end up installed in 20.04, the building of realsense-ros fails and the realsense-viewer isn’t available. I’ve just updated the script to be able to downgrade on Ubuntu 20.04 as well, so you should be able to git pull and run it again to apply the patch.
Looking forward, we’re in the early stages of figuring out the root cause behind the degraded Realsense performance. I have a noetic feature branch that addresses most of the errors mentioned in the Realsense Downgrade post on my robot. We are testing this on many robots before releasing it and decommissioning the downgrade patch. If you’re willing to help us with another data point, I can walk you through testing the branch with your software and seeing whether it fixes the degraded performance.