@brauner @monsieuricon Maybe it could instead allocate you a namespace that you alone are allowed to use? That way you can use whatever ID you want within that namespace and know it's safe.
One thing that I end up doing is generating mails/pull requests with fixed message IDs. This allows me to refer to mails via lore links before they are sent. For example, to mark PR dependencies.
Problem is that they could be grabbed by someone else if I don't send them all at the same time.
Maybe lore could allow reserving message IDs for 24h or sm? @monsieuricon