Sending typing indicators fails if ghost has not yet joined the room

[salixor]

The following error can be found in logs : Failed to send typing indicator. MatrixError: M_FORBIDDEN: User @_discord_<id>:<homeserver> not in room <room>

Example of use case :

• bridge a Discord and Matrix room
• have a Discord start typing
• the error is found in logs

Should ghost users be invited to the Matrix room as soon as a Discord user starts typing ? Maybe as an additional config flag ?