We just released GJS 1.58.0 in the GNOME 3.34 release. I for one am constantly getting confused about the version number because it goes with GObject-introspection 1.62.0 and GLib 2.62.0.
I think this was originally also the case for GJS, but a number of releases were skipped.
I plan to skip a few versions and make the next unstable series 1.63.x and the next stable series 1.64.x (corresponding with GObject-introspection 1.64.x, GLib 2.64.x, and GNOME 3.36.) Any concerns or objections?