No. It was said that Muu can't use techniques like Jinton as his power is halved. [
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] There are no special properties of which you speak.
And of course, Itachi was tired after using Tsukuyomi and Amaterasu, but that doesn't mean he reached his limit. As Itachi said, there was no reason to hurry, as they were confronted with Naruto's power. That confrontation doesn't speak of what Itachi is capable of, but the fight against Sasuke does, as he truly reached his limits there.
Using MS techniques, the PS included, don't drain the Chakra of the EMS user, that's the advantage of these eyes as well. Nobody would be able to use such a construct of Chakra with his own reserves, when already the normal Susanoo strains your body and drains your Chakra that much. The size doesn't speak of the quality, as the PS is twice as big as 100% Kyuubi. Sasuke with his 3.5 Chakra reserves used a large legged Susanoo easily, while a normal Susnoo strained his body and drained his Chakra strongly.
So I assume that Itachi would at least be able to use a larger construct of Susanoo which is also legged. Not saying it would reach the size of Madara's PS. Chakra drain is, as I said, eliminated.