RustyCrab When updating the server the next time, i'd suggest to implemend this pull from rA https://github.com/rathena/rathena/pull/7622 it is merged since end of March so it is stable As far as I understand you can set mapflags to control the ability to respawn in the instance after disconnect. This does not affect respawning after dying.
Muh This is long time implemented already. If there's an instance this doesn't work, feel free to open a bug report.