Correct way to update BIOS

I've read a couple of times on this forum that the correct way to update a BIOS is by avoiding jumps between versions,

here: https://communities.intel.com/thread/51162

and here:https://communities.intel.com/thread/52658

Too bad that I didn't read that in the official documentation, because on my NUC 2820 I've been updating from v. 15 to v. 34 in one single step, and now I'm wondering whether the freezings (and many other problems...) that I'm experiencing are caused by that procedure.

In this case, which is the best way to roll back? Should I go from v. 34 to v. 32 to v. 28 and on and on? And then up again... Or could I just go down directly to v. 21 or even v. 15?

Thanks for your help!