Not sure how that plarform works but have u considered cashing out ur funds using Payoneer instead of ur local bank account? (Maybe split the cash out, so that 50% goes to local bank account which u declare and pay taxes on and the other 50% goes to ur Payoneer account which u dont declare)
Not sure how you can work around the past tax issue....UNLESS, you could tell them that u outsourced the bulk of the work to an overseas service provider in the past and this resulted in smaller profits for u (then u pay tax on the lower profit that you declare) ?