Had the same issue and MR21 is working fine for me. As 'UA-' properties are deprected now, the format should not be supported anymore. The MR only supports 'G-' format, which is correct in my opinion.
But the approach to handle both Formats which was mentioned in the Issue description seems outdated now.
Would be happy if MR21 gets merged!
makkus183 → made their first commit to this issue’s fork.
Can reproduce the mentioned SyntaxError in version 6.0.2
The Update is also necessary for Drupal 9.x. Also not sure how to handle it.
"Solved" it as mentioned in #4 for now..