Yeah, unfortunately the Burnas won't get to shoot turn 1 since they can't advance into range.
I tried a list with 45 Kommandos and Snikrot in it once a few weeks ago, against a Guilliman Beakie gunline with some of the new Primaris stuff, Hellblasters and Aggressors. Right after the new Beakie book dropped. Turns out that was a really bad time/army to test against, because I didn't know all their new Stratagems yet, and I both Infiltrated a unit of Kommandos and Jumped a unit of Boyz within 12" of a big unit of Aggressors that were set up near their Primarch.
Basically what happened was there is a Beakie Stratagem called Auspex that allows a unit to immediately shoot at any enemy unit which deploys from Reserves (whatever sort) within 12", and my particular Ork list was doubly susceptible to this because Kommandos Infiltrate in the Movement Phase, and Da Jump happens in the Psychic Phase, so even with the Matched Play limitation on Stratagem use (only one use per Stratagem per Phase) his Aggressors still got to kill a unit of Kommandos in my Movement Phase, followed by killing a mob of 30 Boyz in my Psychic Phase (not my best game, haha!).
I followed that up by failing charges with Snikrot, Zhadsnark, 20 Stormboyz, and 15 of my remaining 30 Kommandos. It was a short game, and I've not played around with Kommandos yet since.
Having said all that, I do think Kommandos have some good potential. Da Jump is frequently fantastic, so it stands to reason that having a lot of units just appear and Charge alongside a Jumping Mob isn't terrible. I haven't explored it enough yet, but one thing I'm sure of is that if you're going to use Kommandos aggressively, you absolutely have to take the max mob size, because if you try to charge with a small mob, a lot of units in the game will just wipe them out with Overwatch shots.
The other thing is, I recommend having a big mob to Jump up alongside them, and some other fast elements besides; I still think Kommandos + Jump Mob + Stormboyz could be really good, but I didn't play it very smartly, and I played it against an army with literally the perfect Stratagem on the perfect unit with the perfect buffs for wiping huge mobs of Boyz as soon as they appeared. Once I get the Kommandoz some new paint I know I'll give the list another try.
The Universe is Orkdom.
QUOTE (Ork Codex 4th Edition)
Gork and Mork are divine powerhouses, deities so strong they are never truly defeated. They simply shrug off the attacks of other gods with a raucous laugh. Gork grins, bearing his long teeth, and lands a mighty blow on his adversary's head with a spiked club the size of a comet. Mork, the master of cunning, waits until his foe isn't looking before clobbering him with a low blow.