Thanks @ozopals1. I did finally talked to boardroom yesterday...

Thanks @ozopals1.

I did finally talked to boardroom yesterday and yes it is the same as you said.

1.  Can BPAY multiple times.
2.  From multiple accounts.
3.  Must fill the form and send to boardroom or email them.  Yes I did ask a few times and she said we must fill the form and email them or send by post for both methods of payment (BPAY or cheque).

To be safe, I think people should do BPAY before 27th April (then fill the form and email boardroom immidately) even though she clearly told me several times that as long as you do BPAY before 5pm April and if you plan to send a cheque, then please do post it before 25th.  It is your hard-earned money and it would be a terrible thing if you make such a small technical mistake by sending your cheque late (remember cheque takes up to 3 days for them to clear). Believe it or not, some people do make these kind of mistakes.