And.. it's done (Version 3.02 - 26-May-2020).
Update to NWR-radios-leaflet.js to add if(typeof String.prototype.includes == 'undefined') { /* shim function for IE11 */
String.prototype.includes = function (str,start) {
var returnValue = false;
var tststr = str;
if (typeof start == 'number') {
tststr = str.substr(start);
}
if (this.indexOf(tststr) !== -1) {
returnValue = true;
}
return returnValue;
}
}
.. I found that Edge12+ supports the function, IE11- does not. Thanks for the idea to have a shim.
wxradio.php, radios.php add commented-out setting for NatGeo map, and add http-only note to 'Terrain' (stamen.com) map.
Updated the .zip and GitHub distributions.