A proxy, under any definition that I could find, takes the place of the individual holding the right to vote.  Consider the chaos that would ensue if an organization permitted more than one proxy per individual right to vote, sort of an extension of vote early, vote often.

Also, I am going to suggest the two vote limit you are referring to means two votes per lot or parcel, not two votes per owner which surely would give a distinct advantage to any parcel with multiple owners over those with fewer owners - more chaos.  So, a lot with two votes could have two proxies and the proxy could be one individual per permitted vote or one individual with the proxy right to represent both votes, depending upon the rules established by the organization holding the vote.

Perhaps you are thinking of a situation where one individual with the right to vote also holds a proxy for another individual or multiple individuals with rights to vote. In that case, yes, the individual can vote on his or her own behalf and also on behalf of those for whom he holds a proxy.  But in this case the total number of votes remains the same while several votes may be cast by one individual (and one at a time!) if that is permitted by the proxy rules published by the organization holding the vote.  But do keep in mind that a proxy may be instructed to vote in a certain way and contrary to the way he or she would vote on an issue.  That obligation must be honored.  Or the proxy may be instructed to vote "whatever you feel is best."