I don’t hear ‘equable’ used in AUS.

I think ‘equitable’ is used in AUS to mean ‘equally reward/share’ (in a sense of ‘fair work = fair share”.

There are talks in education now about ‘equity in education’ (= equal value for learners) not just ‘equal right to go to school’. This means teachers have to ensure all learners do ‘learn’ (equally). But schools also want ‘equity’. But they mean (equal) ‘prosperity’ - to earn income ;-)