Can a Listener be set to set issue level security based on a custom field value?

[Jon Jones]

I have a post-function set up to use ScriptRunner to set the issue security level based on a value in a single choice select list custom field on JIRA 6.4.12 with ScriptRunner 4.1.3.10.

Is it possible, and advisable to set up a Listener to do the same thing?

[JamieA]

It's fine, I don't see any reason not to do that.