I've just implemented this and posted a beta: https://forums.ni.com/t5/JDP-Science-Tools/BETA-version-of-JSONtext-1-5-0/m-p/4136116
Handles comments like this:
// Supports Comments
{
"a":1 // like this
"b":2 /*or this style
of multiline comment*/
"c": 3 /*oh, and notice I'm forgetting some commas
A new line will serve as a comma, similar to HJSON*/
"d":4, // except I've foolishly left a trailing one at the end
}