Is there some collaboration between iodé and other custom roms like calyx and graphene? Like for bug and security fixes?
I am asking out of curiosity.
IodéOS is a fork of LineageOS, so an exchange is to be expected.
I have to admit that at least a human-readable webpage to which LineageOS version an iodéOS version is closed to would be very nice. Actually, you can only guess if you have a working news app or read (out by yourself) the JSON file in the GitLab page of the project.
That is extremely annoying me. 
I know it’s a fork of lineage and for it’s obvious this collaboration, I am interested in the collabration with other custom roms.
No I don’t think there is, as far as I’m aware of. At least not formally.
Not that I have any inside knowledge, but from what I’ve read around online, there is some sort of (healthy dare I say?) competition/rivalry between some of these ROM maintainers.
Some of these open source projects were already forks born out of rivalries, divergences, different ways of thinking, different priorities, diverging policies, or personalities.
Some developers also like to boast or bad mouth other projects, some see them as competitors fighting for the same “market” or pool of potential customers. This is particularly true for ROMs that are financed through donations or partner sales.
It is a shame really because they could all be on the same boat collaborating towards the same end, but sadly such are human interactions.
In an ideal world, I’d imagine LineageOS, Iodé and e/OS would be one and the same ROM, but I suppose the “informal” collaboration we get in the form of forks and pull requests, etc. is the best we can do, and it has worked so far to bring us what we currently have.
indeed I see a lot of ostility between graphene, calyx, lineage /e and also between mobian, librem5 etc. It’s good to have different OS’es but when it’s about collaboration of bug and security fixes dev should put their ego aside and work toghether.
That could be said about most human made endeavors, but sadly humans aren’t always as great at collaborating as we’d like to.
On the positive side, some times healthy competition can also be beneficial.
indeed, and I am old enough to have lived a lot of stupid competitive battles that lead to nothing.