toggle cosmetic to bottom right corner of black box, crafting to where the toggle cosmetic is, the 2 buttons by the inventory to the config like all other settings, offhand slot to bottom left corner of black box

toggle cosmetic to bottom right corner of black box

The reason for such is frankly the toggle may not always exist if the given entity has any accessories slots but the main entity UI view will most likely exist since armored entities mostly exists like Wolfs, Horses, etc. Futhermore that area acts as a place to put the group filter options that can be toggled in the setting.

... crafting to where the toggle cosmetic is ...

Why would such be any better there? Like its just being moved up and even then there is an option to merge the crafting section down at the bottom to the right of the toggle buttons and offhand slot. It may be better for such a configuration to have the crafting toggle and the settings button be moved to the left side to not lead to constant toggling when crafting but even then its not a big deal I think.

... the 2 buttons by the inventory to the config like all other settings ...

First the toggling of the crafting table is something I see possibly happening for people play style as they may just use the screen as a access for Accessories and the settings are meant to be there as they allow for quick configuration of some of the adjustments present for the UI that has no way to be accessed from the Mods settings as such is linked per instance of the players data i.e. the given world instance

... offhand slot to bottom left corner of black box

Nope as such has a chance for the a given entities saddle (Saddle for horse and Carpet for Llamas) combine with future slots being present there for the given entity.

Overall I do think some adjustments to the bottom section is warranted for the buttons which are planned when I find time to deal with such but besides that the design is not going to change that much.