The Death Stars main laser cannon has horrible accuracy and a slow rate of fire.(The standard trade offs for a heavy weapon as seen in approx 87% of realities.) Well there is a chance of the laser beam hitting a maneuvering Ori warship I find it unlikely.
And, even if it did hit, would the laser beam technology actually have any effect on an Ascended being designed defense shield?
Perhaps through the sheer energy released it would, making it a remarkably crude and inefficient device compared to the APBW's as an anti-ship weapon. But, well the power source of an Ori warship is never officially identified (As far as I currently know.)it may be a device similar to the ZPM....meaning its energy output could be so great the DS super laser would not 1 hit K0 it, making it even less effective as you need to hit multiple times with the agonizingly slow firing weapon. Something to consider.
Most people forget about the Death Stars other weapon systems. It had thousands of turbo laser and ion batteries as well as...what 700 something tractor beam emitters I think.(Why can I remember this stuff but forget to check the mail?*Cough*nerd*cough*) Now, would these weapons have any effect at all on the advanced shields of the Ori? Something else to consider.
As far as its defenses go, I am pretty sure no shield in the Star Wars universe could stop an Ori main cannon, so throw those out the window. But, I do believe the Death stars had kilometers of armor. Would the piercing Ori main cannon be able to go through all that dura steel? Something else to consider.
Well, any thoughts?