Do FDFMerge and FDFMerge Lite support button fields? May 7, 2013 / Judi / FAQ, FAQ FDFMerge, FAQ FDFMerge Lite, Forms Processing Yes. Button fields are supported in both FDFMerge and FDFMerge Lite (version 3.7 and higher). FDFMergeFDFMerge LiteForm Fields