Currently, in the advanced settings, the recipient of a message can choose whether to use Markdown to render the message. I think this can be modified so that the sender of the message decides whether their message needs to be rendered using Markdown. If needed, Markdown rendering will be automatically applied at the receiving end.
In a chat page, whether my outgoing messages are rendered using Markdown is determined by my settings. As for messages sent to me by others, whether they are rendered using Markdown is determined by their settings. In summary, the rendering method of any message is determined by the sender’s settings, so the message needs to include information about the rendering method.
When my friends have different rendering habits, adopting the aforementioned improvement method is quite suitable.