Lulav-shake count varying with shake history

Question

T'hilas Hashem, the standard sidur (prayer book) of the Lubavitch chasidim, includes, passim, rulings of their first rabbi ("the Rav"), copied from his own sidur. The rules printed before halel indicate that one should, on Sukos, shake the lulav in a suka before the prayers begin. If one did so, they continue, then he should shake it four times during halel: once during the first appearance of "hodu", twice during "ana", and once during the last appearance of "hodu". However, if he failed to shake the lulav before the prayers started, then he should shake it before halel and then only three times during halel: once during each appearance of "hodu" and only once during "ana". It cites "R.M." (Ra'ya M'hem'na?) as a source.

Why does the number of shakings of the lulav during halel differ, according to the Rav, depending on when one previously shook it? Why does he prescribe fewer shakings during halel if it was shaken in the synagogue immediately before halel than if it was shaken in suka earlier?

Answer 1

Dayan Raskin, in his notes to the Rav's Siddur, explains that Raaya Meheimna speaks of 72 motions total (18 for נטילת לולב and 54 in Hallel), while Arizal says to do 72 in Hallel alone.

So the compromise is to consider R.M. as talking about where you do נטילת לולב right before Hallel, and then its 18 wavings count along with the ones in Hallel; while Arizal is talking about the case where you do נטילת לולב earlier in the morning.

Answer 2

The idea is that there should be four shakings in shul. If he said the bracha at home in the sukkah then that is seperate and doesn't count as one of the four. However, if he said the bracha in shul or in the sukkah in shul then that counts as one of the four and he only does three in Hallel (omitting the shaking during the repitition of Ana). I assume there is a Kabbalistic reason for doing four and only four shakings in shul.