Honestly, I wouldn't make a mountain out of a mole hill out of Hecklinski getting time. It's true garbage time at the very end of a blowout. Gronowski could have been taken out earlier, but he still needs repetitions badly.
This serves a few purposes. It keeps Hecklinski actively engaged. It signals to a transfer redshirt freshman that he's in the development pipeline.
Brown is a bit further along. Brown got his garbage time against Albany. He got a good stretch of productive playing- time against UMass. Then he got thrust into the biggest game, so far this year. Brown was doing single read stuff in practice. The resulting underwhelming performance, at the end of the hotly contested Indiana game, should be a surprise to no one. He just wasn't ready for that level of intensity.