Here is the dev chat if anyone is interested.
If the "block" function is unselected on the formation do Tight Ends/Full Backs block on running plays? Same question could be asked of Wide Receivers on any given play. (noah23 - Hall of Famer - 6:11 PM)
Yes. Tight Ends, Full back, and WR will all block. The difference is where their blocking influence will occur. If they are set "isBlocking" they will be added to the offensive line and influence very short and short runs in the middle and to the outside. If they are not blocking they will have blocking influence based on there route specification. For example, if a TE has a 50% chance of running a medium route, a 50% chance of running a short route his influence will be split between those two locations.
Chetty: You will notice the pass protection the most defending against blitzing teams. In fact, if you play blitziscoming you better have both TE and FB in and blocking or it will be a long night at the stadium for your team.
nitros (James)