Need help: producing a MULTI-grafted tree ["fruit cocktail tree"]

I want to produce a multi-cultivar Asian persimmon tree, carefully choosing to include only scion wood from Asian persimmon cultivars that are reportedly hardy to my USDA zone (6b).

To start off, I'm purchasing a Diospyros kaki 'Saijo' cultivar which is rooted on a single D. virginiana understock trunk (3' - 5' tall). Ultimately, I'd like to incorporate an astringent (i.e. 'Saijo'), non-astringent (i.e.'Ichi kei jiro'), and pollination-variant nonastringent cultivar (i.e. 'Maru').

My question is this: how can you in-graft scion wood when in situations where there is only a single truck, as opposed to grafting a scion wood cutting into a multi-trunk tree (i.e. when it suckers and forms multiple trunks from the base). Am I supposed to follow a branch to the truck and in-graft the scion wood into a few such main branches? I which there were an online tutorial or good description on how to do this with Asian persimmon trees.

After I've done this, I'd like to produce a multi-cultivar American persimmon tree ('Yates', 'Meader', 'Szukis', 'Rick', etc.) but how can this be done, since American persimmon trees drop their lower branches as they mature; I would think that I could prune the tree in-check so that no main branch (cultivar parent branch) ever dies out, being crowded out and replaced by higher main branches.

Thank you,

Steven

However, I do not quite understand how to in-graft multiple