Yes, this is no problem.
Macquarie establish your account immediately so you can fund it while they finalise your account details (1-2 biz days). You can withdraw these funds or transfer them to USD as soon as they have approved your account.
If for any reason that Macquarie cannot approve your details the funds in the AUD wallet will be returned to you in 30 days after your application. This situation is very rare.
If you account has been approved electronically, we suggest using POLi initially so you can fund faster and then bring your cash back through your AUD wallet once its established (which happens a day or two after the Electronic Verification).