hi,
as a workaround you can publish new attribute in cr factory, for example call it z_assignee_prev (type SREL: cnt).
then create followed files within site/mods/majic folder:
MODIFY cr POST_VALIDATE z_assignee_prev(assignee) 7000 FILTER(assignee{} && EVENT("UPDATE"));
cr::z_assignee_prev(...) {
if (!is_empty(argv[2])) {
logf(SIGNIFICANT, "%s > assignee changed: %s > %s", persistent_id, argv[2], argv[3]);
send_wait(0, this, "call_attr", "z_assignee_prev", "set_val", (uuid)argv[2], "SURE_SET");
}
}
this is very simple customization but I want to warn you that SPL customization is not recommended and not supported by vendor.
Regards,
cdtj