You want to improve his accuracy/completion % ? ??
How about you start by getting him a REAL nfl quality WR/TE and not bunch of practice squad or rejects from other teams , and maybe an OL that could give him more then 0.09 sec in the pocket on 3rd Downs , especially when it’s 3rd & 8, 9 because our running has been practically none existent ,
Hopefully all this will be addressed in the preseason , so having some experience as a starter this year and with a full TC and preseason ( next year) under his belt without having to split reps with other QB’s (IMO) will make a huge difference in his all around performance next season!!!