Asking for melacha on second day Y"T vs. during early Shabbos

Question

If one makes an early shabbos, one may ask a Jew who has not yet accepted shabbos to do melacha for him (based on this answer and its sources). I would assume that, all the moreso, one could benefit from a melacha done by a Jew who wasn't asked. Other than the time concern (how close to shabbos) there seem to be no limitations

But on the second day of Yom Tov in Israel, concerning whether a disapora Jew can ask an Israeli to do melacha for him, Halachipedia reports

Yalkut Yosef (Kitzur S”A 496:27; Chazon Ovadyah (Yom Tov pg 138)) permits a non-Israeli to ask an Israeli to do melacha for him on Yom Tov Sheni. However, Sh”t Igrot Moshe 3:73 and Sh"t Shema Shlomo 1:9 forbid. Rav Elyashiv (in Kuntres Teshuvot siman 54) writes that the only concern is Memotzi Chefsecha which is permissible for a dvar mitzvah.

This doesn't address whether one can benefit from action not done expressly for him or her, but even to the question of asking directly, some opinions absolutely forbid and one imposes limitations.

Why would there be any difference between the application of the law of "asking a Jew to do what you cannot do" in the two cases?

Answer 1

RAv SZ"A in Minchas Shlomo 1:19;3 discusses this exact issue. He explains why it might be different - the reason early shabbos is mutar is because the person only accepted it upon himself because he chose to do so on his own volition. Therefore we say he only accepted things that pertain to him himself but not for the halacha of telling others (levush). On the second day of Y”T it’s not due to the person accepting it upon himself, but rather due to a safek of which day it is, therefore it’s applicable to all halachos both himself and for telling others. Another reason for early shabbos to be mutar is because he had the option not to be mekabel shabbos early and do the melacha himself, therefore he can ask others to do it for him (M"A). On the second day of Y”T he doesn’t have a choice in the matter.

He then proceeds to explain that indeed both these reasons do indeed apply on the second day of Y”T as well. The second day is also only a minhag and not miikar hadin, if it would be because of a real safek then those from Chu”l who are in E”Y for Y”T would only keep one day since it is not a safek in EY. By the fact that they keep 2 days in EY as well proves it is a minhag and is something that we accepted on ourselves of our own volition. As far as having an option to decline to accept it like early shabbos, he says that if a person were to decide in middle of Y"T to live in E"Y he would become mutar in melacha immediately (a highly debatable point between poskim) so he has the possibility to do the melacha himself just like early shabbos.