I'm living in Europe, Sweden, in here we actually have an EU-directive that states the owners right to run the firmware of their own choice and that manufacturers must prove that any such custom software IS the reason a device has failed before voiding any warranties.
But still, I ALWAYS return to stock before any service is done, just to get out of the hassle of explaining this to service companies.
Return to stock, that's what I've have done.
Be happy. It's much more fun that way.
LG G2 802
Google Nexus 4 CM 10.2/Stock - Depends It broke
ZTE Blade CyanogenMod 10.1 KonstaT and gang - Retired
Samsung Galaxy Tab 10.1 CM10.2 Thanks to Pershoot. Loving it. <<<Sill running strong!