I've never seen a carrier. Therefore, I couldn't possibly let that thing go and live with myself afterwards. I'd take my time reloading at depth, sneak up to PD and launch a spread of two or three fish. You can then creep away (very slowly) at ahead slow until the tin cans give up on you. But, that's me.
Of course, after sinking the flattop I'd probably find a way to get my shiny Type XXI depth charged to the bottom. At least I could try to snag the 3rd arrester wire on the carrier's deck with my rudder for style points.
Frustrating situation, though...