First Brisket on LBGE

i've only done one and that was a packer brisket i did it at 265 grid cooked till about 200/205 internal but started checking it around 185 or so for tenderness (sticking my probe in it looking for it to feel like butter ) sounds like you have a flat am not sure in the difference between cooking a packer and flat am sure someone will have a better idea . As for rub and injecting my brisket was done a few hours before putting onto my egg but i've done other types of meat and left them sit over night . slicing slice it against the grain about a pencil width or slightly smaller is what i've read and did . good luck let us know how it turns out