In the meantime? There should be other XML parsers that are not using the built in system. It should be possible to substitute the missing native parser with an actual JS parser.
I'm also dependent on Spriter/CJS in the near future. No option, no work around. So I'm very invested.
it's interesting. I wrote a JSON parser before I even new JSON existed. Amusing story really. I was at the time needing someway to store my level data and test scenes in 3d. I found the overhead to have to compile a new scene test annoying. I recalled I really liked CSS formatting style. So I wrote a parser for CSS. Then I discovered JSON :D
I also had a friend who wrote an XML parser in the earlier days of XML. These aren't rocket science to write. In fact there should be some already. Native to JS. It shouldn't be all that difficult to as mentioned. Substitute all the missing XMLParser object with some one elses.
If CJS isn't out by time I reach the point of no progress without it. Then I will look into doing this. Fortunately most of the technology has been just a little ahead of my needs :)