Earlier quoted context omitted.
this, but I bridged them all to IRC by custom means, which is the easiest to implement and allows people on all platforms to talk in the same channel-equivalent. the media issue is solved by using a more modern client that can generate embeds (e.g. glowing-bear for weechat-relay).
Do you manage to get pictures, audio messages, videos and reactions to work well in both directions with that setup? Also, I use this for personal messages as well as group chats. The people I interact with don't even know I am not using the native client.
custom reactions aren't rendered irc-side, mostly because I can't be bothered, but @mentions and all other platform-specific messages are properly translated.
I considered forgoing the channel bridge and writing a custom IRC server that mirrors a discord/matrix group, but I never got around to it.