When Big Bertha switches to auto or manual mode (even if it's already in the current mode), the artillery snaps to pointing north. Please have it remember which way it was previously facing.

It's added in the next version.

Bug seems to be reintroduced. I can replicate it in the latest 0.5.8 version.

I cannot reproduce it. Works fine for me:
Link to video

Thanks for the video link. I found a discrepancy in our testing.

You tested:
Turret had ammo
Fired at nest
Turret rested at non-default 90, 180 or 270 degree angle
Turret still had ammo
RESULT: Worked as expected

I tested:
Turret had ammo
Turret fired at nest
Turret ran out of ammo
Turret not pointing north (0 degrees)
RESULT: Changing modes makes the turret point north

Turret did have ammo
Turret did not target enemies
Rotated turret to not face north (or used a blueprint for any other angle [vanilla artillery points in same direction while this mod points to nearest 90 degrees])
RESULT: Changing modes makes the turret point north

Hope these results clarify.