61.159 (d)(2)(i) clearly specifies "airplane", so my read is no helo FE time. "Airplane" has a specific regulatory definition in the FARs.

61.159 (d)(2)(ii) does NOT specify airplane, so reading it at face value you "might" be able to count student or instructor FE time in a helo.

I don't think that's actually the intent, I assume they meant it to be the same as (i) so it's probably just sloppy language on the part of the FAA. So they would likely just refuse to follow the letter of the reg.

That's the battle you'd have to fight. If you have significant student and/or instructor time might be worth writing the FAA a letter and asking for a legal interpretation... you never know, might save you some time building. Search their database first, somebody might have already asked the question. Good luck.