NRF multiple connections?

Thanks again, Gordon.

Adding the timeout solved it:

scan( function( queue ) {
    // recurse through queue
    function process() {
      if( queue.length ) {
          transfer( queue.pop(), command, function( result ) {
            console.log( "done" );
            setTimeout( process, 150 );
          });
      }
    }
    process();
  });

150 ms seems sufficient.
I was able to go down to about 145 ms, but everything below still caused some errors.

I'm very thrilled to get the notifications.
Good work - keep it up!