4.3" Display Cape on BBB


Has anybody managed to get a 4.3" Display Cape working on BBB with a recent Debian image (e.g. 8.6)?
I have uncommented dtb=am335x-boneblack-emmc-overlay.dtb in uEnv.txt as per the instructions at https://github.com/beagleboard/bb.org-overlays, which sort of gets the display to work, however the interface is too slow to be usuable - “top” indicates that XOrg has CPU usage >90%.
7" Display Cape seems to work fine.
U-Boot version is “U-Boot SPL 2016.11-rc3-00002-g73df7f7 (Nov 04 2016 - 15:20:36)”

Any ideas?

Thank You

Are you using the 4D systems cape? I have the 4.3 and 7 inch versions of these on several BBB with no issues.