God wills that one be lost or perish. That shuts the whole thing down right there. If He wills none perish, then there is no such thing as Him willing only certain ones to be saved. OSAS believes God chooses not to save everyone, but only some ,and he chooses the rest to go to hell. They hate putting it that way, but that's what OSAS essentially is saying.
2 Peter 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.