To be fair, this is not as lavish as it seems at first glance. There are a max of three DOFFs you can stack in any one specialization; this means you have three 30% chances of a proc; and those three chances only get rolled once each, after each time you use Brace for Impact. (You actually have two green 20% DOFFs and one blue 30% DOFF, it looks like; but I am going to pretend they're all 30% chances in order to make the numbers simpler).
So you're not going to get separate rolls on the shield HoT and one-shot regen; it's a single roll for each DOFF that he might do both of the things that are listed. In other words, you don't have a 30% chance of +1,148 and another 30% chance of 442 / 15 sec; you just have one 30% chance that both things might happen. So what this comes down to is that you have three 30% chance rolls to get what amounts to an extra TSS proc, each time you use BFI.
For the statistically challenged, the chance of getting at least one hit on three rolls of a 30% chance is 65%. That means about 2 times in 3 when you use BFI, you get a bonus TSS proc after you use it. And keep in mind, you only get this if you use up THREE of only FIVE active roster slots in order to get the maximum stacking on one active roster ability like this.
This is assuming that stacked DOFFs will not double proc (i.e., that if one of them succeeds in procc'ing on a given use of BFI, then the other two automatically will not, either by some lockout, or just because the rolls on identical DOFFs halt once one of them succeeds). As far as I know, that is in fact the way it works; but if it's not, then it definitely should be.