Provided always nevertheless, that nothing in this Act contained shall be construed to extend to exclude any cottager, or other person or persons whomsoever, having right of common, and having no land in any of the said common fields, from having and enjoying his or their right of common in as full and ample manner as he could and might have enjoyed the same before the passing of this Act, unless each cottager or other person shall, at any meeting to be held by the occupiers of such common field lands, in manner aforesaid, consent or agree in writing to a composition for such right by an annual payment, or other annual advantage or compensation, or to a limitation thereof; in which case such consent and agreement shall be binding and conclusive upon every such person so agreeing, his heirs and assigns, tenants and occupiers, until such time as the rules, orders and regulations for the ordering, fencing, cultivating and improving of the said common field lands existing at the time of giving such consent shall expire.