Preface: I don't know if the devs will even read this, and sorry if this isn't the right place to put this. (crossposting with the subreddit)
Whether Engagement Distance is set or not, ships go straight forward towards the enemy until they move into range to attack. Ships that engage from the Side then proceed to turn 90 degrees and fire.
Side-firing ships don't seem to maintain Engagement Distance, at least not well at all. This is especially important for ships who want to maintain a range advantage, for example, Corsairs with Runic Targetting upgrade, and long-range Chaos ships. They seem to turn at most only like 5 degrees to move away from the enemy.
My suggestions with an example is this: You have a targeted enemy ship that has a weapons range of 9000, and you have a ideal/maximum range of 13500 (or even if they have Macro weapons while you have weapons like Lances.). It's in your advantage to keep distance from the enemy.
The first suggestion is that 1) when your ship enters the distance bracket nearing the desired Distance (which would be 13500 to 18000 here), it turns to a 40 degree angle to still be closing in, ready to a) fire weapons or b) launch a Boarding Action for ships set to 4500, etc.
- When your ships are inside of their Engagement Distances, they then turn away to 40 degrees to better distance itself from the enemy while still be able to fire.