I’ve gotten to the point where I use the internal temp (I like 195ºF) as step one in determining whether a pork butt is done. Once the butt hits 195ºF, I’ll see how easily the probe goes in and out of the butt in various places. Sometimes it’s like butter, in which case it’s done. Sometimes I get more resistance, at which point I’ll let it go longer.
From the description of your butt with the globs of fat, I’d bet that probing it would have given you some resistance.
I generally plan for 1-1.5 hours/lb. for a bone-in pork butt, cooking indirect at 200-225ºF according to the dome thermometer, with the meat on the main grate. so your 9 hour cook time seems reasonable.