Cosmetic Device Status Normal Modification
A quick hack: have the Status screen in Settings display Normal for device status as opposed to Modified. This mod is a superficial one - it does not circumvent SysScope's checks for determining whether your device has been rooted etc., so you still won't be able to use OTA updates. Personally, I always flash with (Mobile) ODIN anyway, so not a problem for me. (Plus, on the Galaxy S3, updating OTA updates your bootloader to a version where Triangle Away doesn't work quite as effectively.)
Oh, if possible, please do reflash a stock, clean firmware before sending your phone back to Samsung for any possible repairs. Regardless of whether your phone displays Modified or Normal, I imagine Samsung would refuse to repair any phone where they see Superuser, SuperSU etc. installed. I do not support the use of this as a means of tricking Samsung for warranty purposes.
I've only tested this on my Galaxy S3 running XXELL5, but the mod is so simple I imagine it will work on any phone where Samsung have put SysScope into place.