I suggest to reuse the positive experience of ReactOS and migrate the code development and issues management to GitHub.
Probably main site pages too. It will give also much easier bug reporting, process of sending patches will be much easier, will attract new contributors.
Perhaps we could follow the example of flashrom successful open source project. They have:1)
"official primary" repository - https://review.coreboot.org/#/admin/projects/flashrom
It is hosted on their own platform, and from this "1)" repository everyone is cloning their source before building it2)
"Github mirror" repository - https://github.com/flashrom/flashrom
Which is actually not just a simple mirror, there are also supported issues and pull requests
that, if they are accepted by maintainers, will be merged to the "official primary" repository as well
This approach will unite the two worlds:1)
"oldbies", the core members of KolibriOS community, would continue using your current repository because they are already used to this workflow2)
"newbies", who are already familiar with Github and just want to make a quick Github pull request without having to learn how to use your infrastructure
Regarding your poll - "Migrate to GitHub? [Yes/No]" - I voted "No" because I don't think it is a good idea to just destroy the current infrastructure and just jump to Github - because that will make us 100% dependant on Github and its' problems.
Sometimes, although rarely, Github experiences the downtimes and significant slowdowns, sometimes it could be mistakenly blocked at Russia by Roskomnadzor for a few days, also KolibriOS could mistakenly receive a DMCA from some troll company and Github instantly complies with DMCA requests so the KolibriOS repository will be temporarily unavailable, etc. So it would be stupid to just switch to Github. However, we could preserve the current infrastructure while making Github an alternative way to get the people's code into KolibriOS.
These ways are not mutually exclusive, they could co-exist