Why don't you test it yourself before you jump to conclusions?
No. It doesn't look like it, it really does mine 2 block in one burst.That's because it does 10 ticks on the first block it touches in a burst. If you do 20 damage, you'll mine a block, and when another pulse begins immediately after that, it would seem like two blocks are mined in one go.
Your math is useless when the game doesn't do what the math says. I don't think it's lag, but lag prevention in the shape of a hard cap.I doubt that is true. It can salvage a maximum of 1 block per tick, but the tick time is 0.025 / 5 = a very small tick time. And one burst is 2.5 seconds. Do the math, and I think you'll find that it can salvage a lot more than 22 blocks per burst. The lag might be preventing the game from mining more than a certain amount, but I guarantee that the maximum amount of blocks per burst is a lot higher than 22.