1. The OP said that since the Holy Corps maked Love Train, it would be 2-A (in my case, possibly Low 1-C)
2. TA4 isn't HDE, the infinite spin
GRAVITY is, and we can belive Gravity is 5D since it's where ANYTHING originates with all the concepts. also TA4 was overpowering the Dimensional Barrier, and the Jojoveller explain how he can do that.
3. No Love Train isn't a multiverse, it is maded of the multiverse, maded of infinite Neighbor Dimensions, and yes it does qualify, i saw more stuff with less context (DB Low 2-C based on it's a reallity). We assumed the barrier was High 3-A, but since he said Neighbor Dimensions which are other
universes. JoJo multiverse is Kind of Level II Multiverse type, and trascending the dimensions would mean that they had the fraimwork of the spacce between dimensions, that is 5D itself.