It's all good.
As long as you have root or enough access to do a dd if=
flash of the recovery image your phone will never know the difference.
However I cannot guarantee the result of changing your system or other files.
The recovery will be no problem.
But be smart.......Backup your phone partition for partition......
no onandroid or twrp backup alone use all !!!!!!! Onandroid + TWRP if possible + look for a factory rm that is currently flashable + do the below ( BACKUP EVERY PARTITION OF THE DEVICE)
do cat proc/emmc or cat proc/mtd
fully copy every partition of your device before changing anything.
If you can do that then I assume you are familiar with the ( dd if= ) command of the adb shell.
You get a complete backup of every partition of the device and I will show you a way in.
Provided you understand the Meta-Inf UPDATER-SCRIPT.
Technically the Edify Script.
If you have no idea what i'm talking about then this will not do you any good.
Otherwise lets do this.
I will patch your recovery if you send it to me. Use dd if= or flashify to pull it from your rooted device.
I will send it back patched and with a script to sign the zip files.
I will sign some tester zips for you if you like.
Worse case scenerio. As long as you cand adb flash dd if= the recovery.img or even better if you can Fastboot flash recovery recovery.img we can allways fix your device.
Do some testing. See what kinda ADB or Fastboot access you have in recovery or fastboot modes.
No matter what flashing a bad recovery will not boot loop you.
The recovery simply wont load.
Reflash the original recovery and you are as good as out of the box.
WANT TO GET OUT OF THE BOX.
Well lets do this. ~