renice 1 `cat /syspart/applications/standby/background/tasks`
does not work because there no dir after /syspart/ if using speedpatch (cgroup).
So for speedpatch code is

renice 1 `cat /dev/cgroup/cpu/applications/standby/background/tasks`

also testing
renice 1 `pgrep browserd`
renice 1 `pgrep image-viewer`
in cpu_sleep

and in cpu_normal

renice 0 `pgrep browserd`
renice 0 `pgrep image-viewer`

will report ASAP if this improves anything.