Interesting.
COD shows that 'beef' (=meat) has two plurals, 'beefs' in US and 'beeves' elsewhere, although as it is normally used as an uncountable / non-count noun, they both seem strange.
'beef' (= 'gripe' or 'complaint' ) which is a count noun, apparently has only one plural: 'beefs'.
Just out of curiosity, I wonder if 'beeves' is in Chi's lexicon? I can't remember it ever appearing, but it's possible (with, eg, 'reversible' as a potential keyword)
MK