This has been working well for me. You've got leg stimulation twice a week. Shoulders get hit twice a week once on your chest day and then again on their own day. A nice big back & hamstring workout after your rest day. You can still smash shoulders ( I love doing this) without worrying about any pressing DOMS as it'll have been 4 days since your chest workout.
The grip work isn't necesary but is something I'm currently trying to improve. This could be calf work if you feel the need. The days I do it on aren't set in stone. I did used to do it on my quads day but my bars too cold to hold onto right now so I do it the following day with chest. Doing it after having hit Bi's means I've already got some pump and lactate build up in my forearms so helps the endurance side of things.
Probaly the best split I've come up with in that your DOMS won't affect the following workout
although my hammies are still on fire from my back workout on Sunday!