\DeclareDocumentCommand \newjfontfamily { m O{} m O{} } {
\cs_set_eq:NN \fontspec_set_family:Nnn \ltj_fontspec_set_family:Nnn
- \newfontfamily #1 [#2] {#3} [#4]
+ \newfontfamily #1 [#2,#4] {#3}
\cs_set_eq:NN \fontspec_set_family:Nnn \__ltj_orig_fontspec_set_family:Nnn
}