It's pretty straightforward to configure - Arch have a decent guide on their wiki: https://wiki.archlinux.org/index.php/Isync
Edit: Arch seems to suggest running mbsync under a global systemd unit - user units are more appropriate for this task - my units can be found here: https://github.com/rdark/systemd-user-units
Do you have a config posted anywhere? I'd love to see exactly how hard it would be to switch.