@mike When it comes to groups that deal with exchanges between different groups, there is no problem. There is the group specification that you use for this.
Using @tagesspiegel@flipboard.com as an example, you can see that this account does not behave like a normal account. Instead, it is a "group" type account.
It looks like all accounts below @Tagesspiegel behave like group accounts. I suspect that this is an attempt to combine different accounts into one root account. But that's not what this type is for.
Why don't you create your own account on a platform that has group functions and observe the behaviour for yourself? I can't describe it in a few words.
Since Mastodon does not support the "group" account type (like many other functions that are standard in the Fediverse), it would be an advantage if you would take the different platforms into account when implementing further functions on Flipboard. In this way, further inconsistencies can be avoided.