Hi Schimon,
The XSF has recently shut down a 'jdev' mailing list. As far as I understand, it was mostly inactive. I'm certainly not against creating new mailing lists (or finding any other solution), but for the time being, let's address the most pressing issue: you wanting to discuss things and not finding an appropriate channel to do so.
I suggest that as long as more appropriate venues are unavailable, you have those discussions here, on the "standards" mailing list. That is in line with what was suggested when the "jdev" mailing list got switched off.
If it turns out that your discussions spark enough interest, that would be all the more reason to start working on a more appropriate solution. In the meantime, it unblocks you.
Kind regards,
Guus