Opposite the mini notrump, there is no reason to use transfers or many of the other accoutrements of standard notrump systems. Accordingly, 2, 2, 2, and 3 are nonconstructive improvements of the contract.
In a game where the mini notrump system is used, it's not necessary to use transfers or most of the typical elements of a standard notrump system. Therefore, 2, 2, 2, and 3 are not helpful in establishing a strong contract.