Yah I don’t see why not. Technically I would allow a nk 1-2-3-4 ect to be used all at once. However the rules stand. That becomes permanent, you would need to find the next mk x that you need in sequence. Of course the combined cost would be a factor too. Such a procedure would be traumatic and potentially life threatening, a good opportunity for a gm to throw in some good role playing.
If you use a mnemonic editor, you can undo 2 character levels’ worth of decisions about which class levels you took, which feats you selected, how you applied any level-based increases to ability scores, how you assigned new skill ranks, and so on. All decisions you made as a result of advancing over the previous 2 character levels you gained are undone. You then make new selections, including new class levels, feats, skills, and the like, as if you had regained the 2 missing character levels. Go through the normal process of advancing your character through each of these 2 levels.
You UNDO DECISIONS, not levels. If you're level 5 and use the mnemonic editor you undo all the decisions of level 4 and 5, if you use it again you're still just undoing all the decisions of level 4 and 5.
Not really. It could be that they only want to change one thing, but it's one thing from more than two levels ago.
"I wish I took weapon focus with heavy weapons, instead of longarms. If only I'd known gunner harnesses would exist someday!"