You need to set up a custom morph in the tail to match the morph you are applying to the figure, adjust the rigging to match, and use ERC Freeze to link the adjusted rigging - DS knows to adjust bones in fitted items to folow the identically named bones in the base, but it doesn't know what to do with custom bones that don't have a match in the base figure.
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You need to set up a custom morph in the tail to match the morph you are applying to the figure, adjust the rigging to match, and use ERC Freeze to link the adjusted rigging - DS knows to adjust bones in fitted items to folow the identically named bones in the base, but it doesn't know what to do with custom bones that don't have a match in the base figure.