Should an acknowledgment be regarded as valid if it does not comply with the forms of acknowledgment set forth in the appendix to the Short Forms Deeds Act (33 M.R.S.A. §775)?

Yes, provided that the acknowledgment meets the requirements of the Uniform Recognition of Acknowledgments Act (4 M.R.S.A. §§1011-1019).

An acknowledgment should be regarded as valid if it complies either with the Uniform Recognition of Acknowledgments Act or with the forms of acknowledgment set forth in the appendix to the Short Forms Deeds Act. In particular, the Uniform Recognition of Acknowledgments Act makes acceptable all forms of acknowledgment that contain the words "acknowledged before me" or their substantial equivalent. See 4 M.R.S.A. §1014(3).