not sure if this is D-I able i know through using sour bair to jab lock its possible to confirm into 60+ percent in a string like tis on much of the cast at 0% It looks good it just seems so wacky that in this instance it was true. did you test it on more than just bayo?
jab>grab>pullemx2>fthrow(this is where it becomes semi true as the tech has to be missed)>sourbair (jablock)>Nair 1>jab>grab>pummelx2>DED down this should net you around 65ish percent if executed correctly, at higher percents take out the jab into grab
As for true combos out of F throw every roy seems to like a different setup. ive seen people just go for DED to rack up consistent damage or like myself go for nair strings and air dodge traps/reads. dependson the opponent I suppose.