Label (L) property is still used. None of presentation alternatives in format version 4 can fully replace L property. Intention is that L property will be replaced by some Go-Write specific extension at some later time.
GOWrite uses GOWrite-specific SGF property GOWRITEFG in figure definitions.
If character cannot be presented in files character set, character is encoded as \uxxxx in file. This is supported only until GOWrite 2.3.1.
GOWrite does not protect user against breaking (some of) rules of FF[4] in all cases. This will improved in later versions.
Things implemented after 2.2.0
GOWrite 2.3.3 can read UGF (.UGI) formatted files. UGF presents diagrams quite differently from SGF, and this may lead to somewhat imperfect conversion.