Depending on your height and weight, an inch on your arms or pursuing larger delts is probably going to require you to add significant weight all over your body. Want bigger arms, deadlift and squat bigger weights.
I doubt there’s any issues with doing 3-5 sets of 6-10 reps of curls at the end of your BBB workout. BBB is assistance, and you can accessorize how you see fit to bring up weak points like delts or biceps - but don’t do it for cosmetics, do them because they are weaker and you want to make them stronger to help you with your pressing and pulling. I can assure you there’s no better exercise than weighted chin-ups for arm strength and size.
Keep a band handy and do band face pulls or pull aparts between bench and press to keep your rear delts and shoulder girdle healthy. Add in some lateral raises 3-5x10-20 once or twice a week.
Another thing you could do is BBB template 2. The volume is the same, except you press 5x10 on bench day, and bench 5x10 on press day. With that template you’re hitting those movements twice a week, which should help to bring up your shoulders. You can do it in that fashion and simply add curls as an accessory.
Also, if you’re doing chin-ups twice a week for 5x10 - that should be enough for your biceps (in my opinion). If you can’t do 5 sets of 10 chin-ups, use the lat pulldown.