I'm not sure if anyone has ever held out a whole year and gotten tagged again, but the widely held belief is that if he holds out the whole year, that he can be franchised again for the exact same amount. (1)Also, if he doesn't get the 6 games, he could be franchised for the same amount.
(2) Bell and the Steelers also disagree about the Transition tag. Bell's camp is saying that it's based on his offered contract salary (Franchise $$) but the Steelers are saying it's based on his paid salary (however many games he plays times $800k). That would be a huge difference in money.
1) This is based on the understanding that he has to play this season for a franchise tag next year to count as his "third" tag. I disagree with the way that Hankmoody is interpreting the CBA, but I'm not legal expert enough to say he's wrong.
IF, however, you do operate under the assumption that he needs to sign the tender to avoid the same franchise tag, the assumption that he needs 6 games to prevent being franchised at the same amount is an inaccurate conflation of 2 separate aspects of the CBA.
1-For a player to get a season to "toll" and count towards accruing a season towards FA, he must play at least 6 games. However, this is irrelevant for Bell. He already has 5 accrued seasons. You only need 4 to become a UFA if not tagged or in a contract. If Bell doesn't get 6 games this year, his 2018 season won't toll, but he'll still be a UFA if he doesn't get tagged and isn't under contract.
2-Players who have been tagged must sign by week 10 (the exact date is 11/13) in order to play at all that season.
So, it seems like these 2 points have been (erroneously) linked. Bell has to sign by 11/13 (true) to play in 2018 and avoid getting tagged for the same amount (assuming Handmoody is incorrect) and Bell has to get 6 games for his season to toll (true). Therefore Bell has to get 6 games to prevent being tagged for the same amount. That is false. If Bell signs at 3:59 on 11/13 & Pitt places him on the exempt list for 2 weeks (weeks 11 & 12) and he plays in weeks 13-17, he only gets 5 games. His season won't toll, but he doesn't need it to, as he has already accrued enough seasons to be a UFA if not tagged/under contract. He would have played in 2018 under the second franchise tag. So, Pitt would either have to tag him at the QB level, or let him become an UFA. HE DOESN"T ACTUALLY NEED TO PLAY 6 GAMES.
2-This is largely irrelevant. If it happened, it would be contested by Bell/the NFLPA, but the Steelers won't do this. Here's why:
If they transition him, he can get offers from other teams. When he gets an offer, the Steelers get the chance to match it. If they refuse, Bell gets the contract from the other team, and Pittsburgh gets nothing: no compensation from the other team & no comp pick. So, if the Steelers were to try to do this, they'd risk getting nothing for all the drama they went through this year.