Whether a defendant can make a knowing and voluntary decision under a conditional plea agreement when, believing he is preserving his Motion to Dismiss regarding the statute of limitations, the Federal Appeals Court limits its review and frames the District Court's decision in a manner that functionally convert is to a non-dispositive one?

Whether a defendant can make a knowing and voluntary decision under a conditional plea agreement when, believing he is preserving his Motion to Dismiss regarding the statute of limitations, the Federal Appeals Court limits its review and frames the District Court's decision in a manner that functionally converts it to a non-dispositive one?