I understand that officially, the latest stoneblock 2 update is a non-stable version, however, I keep running into this same problem, over and over and over again that's solved in the latest version of mekanism: Large multiblock structures that were previously loaded will crash your game due to a nullpointer because the game didn't receive the entire structure at once. Since I'm fairly certain that this mek update also affects server-side aspects (since other things were also done) I'm unable to just download that update and drop-in replace it. This latest version of mekanism is in the latest Stoneblock 2 update, and I know that people other than me have been burned by this problem as well (unfortunately). I can stop this for myself by removing 1 block from the multiblock so it's no longer formed, but sometimes I forget to do this and that causes problems for me, and people who may visit my base if I forget about this. The problem is hard to solve for me too because just turning it off means that I have very little power generation otherwise, and would have to essentially spam large amounts of other generator kinds (10 rainbow generator's worth of power I make with the multiblock). So I'd really like to have this done, but I understand if this is a "no".
Hm, FTB normally changes it to release version after a week. I will ask around if they can change it out of beta.