From what we know so far, the Mobile Firing Arc works like an Auxilary Firing Arc which you can move to point left, backwards, right or if you really, really want, forwards. The Mobile Arc can be switched to any quadrant with a Rotate Arc action. At low PS this means you can be arc dodged: at any PS repositioning the arc frequently costs action economy.

As it's a firing arc I'm fairly sure R1-2 does not trigger Autothrusters.

So, if I were to houserule mobile arcs onto the YT-1300 and VT-49 how do you think it would affect them in terms of balance and in terms of enjoyment?

From what we know so far, the Mobile Firing Arc works like an Auxilary Firing Arc which you can move to point left, backwards, right or if you really, really want, forwards. The Mobile Arc can be switched to any quadrant with a Rotate Arc action. At low PS this means you can be arc dodged: at any PS repositioning the arc frequently costs action economy.

As it's a firing arc I'm fairly sure R1-2 does not trigger Autothrusters.

So, if I were to houserule mobile arcs onto the YT-1300 and VT-49 how do you think it would affect them in terms of balance and in terms of enjoyment?

They are overcosted if their turrets are dropped to Mobile Arcs, either discount their points or give them two arcs minimum and a free action to rotate arcs.

I would take off 5-10 points. The shadowcaster looks like it requires an action to adjust the arc. That's a huge loss in output to use a turret. But an interesting fix to the clunky and unnecessary feel of similar fan made ideas.

What TTR said. It's a huge hit to action economy, to your ability to target enemy ships, or possibly boh. I'd have to playtest to be sure, but a 5-point discount seems like a decent starting point. (Basically, subtract the price of Boba Fett from the price of Dengar + Punishing One, fudge a little for the differences in PS and pilot abilities, and that's roughly what it's worth to step back from a PWT to an aux arc.)

What TTR said. It's a huge hit to action economy, to your ability to target enemy ships, or possibly boh. I'd have to playtest to be sure, but a 5-point discount seems like a decent starting point. (Basically, subtract the price of Boba Fett from the price of Dengar + Punishing One, fudge a little for the differences in PS and pilot abilities, and that's roughly what it's worth to step back from a PWT to an aux arc.)

I was thinking perhaps instead giving them a combined arc bonus like the Shadowcaster title has: if you've got both forward you'd get an extra attack die.

I'd honestly trade the turret on the falcon straight up for a mobile arc. On PS 9 Han, it'd be amazing! You could shut down autothrusters much more easily by just rotating the arc! And you could make up for the lack of offensive actions with things like predator, gunner etc.