I have noted the previous long thread from anriard and have to agree this crossword is a stinker. I am too stubborn to give up and hope someone can give me a leg up with:
20a: Go on board immediately after this cautiously optimistic forecast? (7) M*Y****
4d: Forte! Is it that of a tattooist? (3-8) E**- *I****I**
I have found some of the answers I have are (to me) unparseable, but I now accept defeat at the hands of the setter.