I don't think you will have a problem. Per Logans discord post:
_@everyone PayPal campaign is back up on the site if anyone who missed the last few are interested in Pre-Alpha or Alpha access. However, I would recommend waiting until after Pre-Alpha to make a decision, unless you can't wait 23 days for the next next phase or really want to support/help us with testing _
He seems to recommend waiting until after pre-alpha to do it unless you really want to test early. I would assume that means you will have the option post pre-alpha.