It's done when it's done. Probe that flat for tender. Start probing with an internal temp of about 190*F.
If you do not have a accurate internal meat probe, treat it like ribs and do the flex test.
Weber WSM, Weber GA, Weber Spirit S-320, Weber 22" OTG
Charbroil Oilless Turkey Fryer
Wife LuzziAnn 1956 model.
Maverick ET-732, Superfast LSU Purple Thermapen & ThermaPop, Party Q