Great work on deciphering this! I was never able to see any of this, so I just did some dirty HTML scanning. It works, it's not great, but it does definitely work well.
I should definitely work on porting your Python SSE to NodeJS (I don't actually like Node, but Piston has been iffy in the past few months, while steemjs-lib has been reliable) rather than using my HTML hacks.
The most important is that your solution is stable, therefore there is no need for changing it. But feel free to port it to NodeJS. It seems I need to check steemjs-lib as I did not pay much attention about it yet.