I'm trying to convert PostScript Type 1 fonts to Open Type fonts. The conversion seems to work, but some of the converted fonts are still showing as PostScript Type 1 in the Font Book.
Everything is correct.
If the exported OpenType (.otf) font has GSUB (glyphs substitutions) or GPOS (glyph positioning) table Font Book shows "OpenType PostScript". If there is no GSUB or GPOS table, it shows "PostScript Type 1". This is how the Font Book works.
The fact that the font doesn't include positioning or substitution tables doesn't mean it is not an OpenType font. But this is the reminder to check kerning (the distance between particular glyphs) in the source font. If kerning was there in the source Type 1 font and the Font Book shows "PostScript Type 1" after the conversion, it means kerning might be lost. To not loose kerning on macOS, you have to open the suitcase font file (not printer file) with TransType.