[mythtv-users] rpi3 & v31 mythtv-light deb package

[Tim Draper]

i've upgraded my mythtv deployment to v31 (from v30), BE first, then my Shield primary FE, and now the rpi3's.

rpi3's are having major performance issues both in the menu and video playback. menu you can see the fade transitions stutter through and it's generally slow&laggy response. htop shows low CPU usage. Video playback is running maybe 1-2fps and maxes out all 4 cores. 
v30 was via https://www.mythtv.org/wiki/MythTV_Light. since there isnt an rpi3 specific build for v31 (and rpi specific codec has been depreciated in favour of v4l2, so i assume we're using a generic package now) i've installed the mythtv-light deb package: https://dl.bintray.com/bennettpeter/deb/pool/myth31/m/mythtv-light/:mythtv-light_31.0-16-ga465f1b03d-0_armhf_buster.deb which is where i currently am.

the playback profile has been updated to use v4l2 codec and both my rpi3's are codec licensed. 

is there a current v31 guide on rpi(3) deployment i've not found yet, or can anyone help out with suggestions on fixing this?