[Galaxy Note 4 Original Android Development] ph03n!x:
Not an Edge user - wanted to buy one but getting it over here is a feat, and the price difference between 4 & Edge is like $300 approx when I got my 4 - so can't comment about the edge screen.

I've been following [MENTION=4824728]Pafcholini[/MENTION] and Emotroid from Note 2. From that, I can say, their kernel is stable- but the configuration can be adapted & improved for individual requirements- and there's no such thing called stable/ retail-ready in after-market development, there'll always be scope for improvement even after the device is end of life and then some - I still use a HD2 and am working on source-built marshmallow for it in my free time, the device had been buried by HTC 5 years ago, and it shipped with Windows Mobile 6.5 :-p

I have never been a fan of Synapse or Kernel Aduitor and prefer hand-tuned scripts. An excerpt of my configuration that affects performance and heating - in case you want to try:

#Thermal
echo "Y" > /sys/module/msm_thermal/parameters/enabled
echo 1 > /sys/module/msm_thermal/core_control/enabled
echo 65 > /sys/module/msm_thermal/parameters/limit_temp_degC
echo 70 > /sys/module/msm_thermal/parameters/core_limit_temp_degC

#Governor
echo interactive > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo 1 > /sys/devices/system/cpu/cpufreq/interactive/io_is_busy
echo 40 883200:50 1497600:70 2035200:90 > /sys/devices/system/cpu/cpufreq/interactive/target_loads
echo 60000 > /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
echo 1497600 > /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
echo 70 > /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
echo 30000 1497600:60000 2035200:90000 > /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
echo 30000 > /sys/devices/system/cpu/cpufreq/interactive/timer_rate
echo 30000 > /sys/devices/system/cpu/cpufreq/interactive/timer_slack

chmod 444 /sys/devices/system/cpu/cpufreq/interactive/io_is_busy
chmod 444 /sys/devices/system/cpu/cpufreq/interactive/target_loads
chmod 444 /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
chmod 444 /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
chmod 444 /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
chmod 444 /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
chmod 444 /sys/devices/system/cpu/cpufreq/interactive/timer_rate
chmod 444 /sys/devices/system/cpu/cpufreq/interactive/timer_slack

# Intelli_Hotplug
stop mpdecision
echo 0 > /sys/devices/system/cpu/cpu0/rq-stats/hotplug_enable
echo 0 > /sys/module/msm_hotplug/msm_enabled
if [ -e /sys/kernel/msm_mpdecision/conf/enabled ]; then
echo "0" > /sys/kernel/msm_mpdecision/conf/enabled;
fi
echo 0 > /sys/kernel/zen_decision/enabled
sleep 1
echo 1 > /sys/kernel/intelli_plug/intelli_plug_active
echo 1 > /sys/kernel/intelli_plug/cpus_boosted
echo 1 > /sys/kernel/intelli_plug/max_cpus_online_susp

#CPU Boost
echo "N" > /sys/module/cpu_boost/parameters/cpuboost_enable
echo "N" > /sys/module/cpu_boost/parameters/hotplug_boost
echo "N" > /sys/module/cpu_boost/parameters/wakeup_boost

#IO Scheduler
echo noop > /sys/block/mmcblk0/queue/scheduler
echo noop > /sys/block/mmcblk1/queue/scheduler
echo 512 > /sys/block/mmcblk0/queue/read_ahead_kb
echo 512 > /sys/block/mmcblk1/queue/read_ahead_kb

#Work Queue
echo "Y" > /sys/module/workqueue/parameters/power_efficient

While most of these are not directly relevant, I suggest you look up Google's documentation of the interactive governor, especially the target_loads and above_hispeed_delay parameters.

While it's always good to get hands-on and build your own kernel, please do so without seemingly being critical of devs - they're working purely because of their passion, and have absolutely no necessity to meet your, mine or anyone else's requirements. If you're not in a position to applaud, donate or support them, please don't be critical of what they're doing or not doing - after all, Samsung took your money and didn't give you enough, which is why you're here first place! No offence meant, just my $0.02!

---------- Post added at 07:44 AM ---------- Previous post was at 07:37 AM ----------

Have you tried flashing a custom recovery through ODIN, manually rebooting from download mode to recovery, and flashing the latest Super SU? I looked up the sources of both 4 & Edge, and couldn't find anything that'll stop this from working on the Edge - esp. when it works for the 4.