We don’t have a policy on doing cross bans between services. We don’t even do cross bans between our own communities (such as Discord bans leading to PNID bans). The only time we do cross bans, typically, is between other Discord servers (depending on the ban). Especially when the bans happen on servers we are close with. If you aren’t welcome in those communities, you typically aren’t welcome in ours either.
Though to be frank, I don’t see the issue with cross platform bans. It’s not something we actively seek out, but if someone on our platform is being a menace somewhere else then I see no reason to let them bring that to our communities? I don’t particularly care if it happened “off platform”, it was still that person who did the actions. Doesn’t really matter to me where something happened, just that it did.
But again, this isn’t something we even have a policy on? Unless you’ve seen instances of this happening, I’m not really sure what the point here is?