OK, let me try something.
Hello @Gargron@mastodon.social! It’s the first time I’m addressing you, so let me first of all say a big THANK YOU for your contribution to the #Fediverse! The reason I’m writing this is that I saw that @mastodon recently announced quote posts - I think that’s a great decision! As you probably know, #Misskey and #Calckey already have an implementation for quotes, where the quote appears under the original post (like a comment, but flagged as a quote), and where the original poster is notified when quoted.
I don’t know how you intend to implement this feature in Mastodon, but since our users interact with each other, I thought it would be a good idea to suggest some direct communication with @syuilo@misskey.io (who originally implemented this in #Misskey) and @kainoa (our lead dev at #calkey), to make sure our implementations will be compatible. Even if there are concerns and things that you’d prefer to be done differently, I think that they should be discussed, and #Misskey and #Calckey should consider adjusting their implementations, so that they interoperate seamlessly with yours. The idea is, let’s see if it’s possible to find a common way to do this, so that users have a smoother, safer and more consistent experience, on such a sensitive issue!
I think that the widest possible interoperability in the #Fediverse is to everyone’s benefit, and it gives a better experience for every #fedizen, no matter what platform they’re on. Let’s try to work closer together on common features or problems and find common solutions - we’ve got this. 
Posting this publicly because I think that more cooperation between fedi platforms is something many people in here would love to see – myself included! Hoping this is received positively and in good faith. United fedi is best fedi =) 
