That's a clever workaround. I like it, and the point was the ability of the gigantic cannons to hurt whether you liked it or not. Let me think some more about whether or not we should allow more than one die to be spent for the direct damage. The light carrier could only use that for three damage, and would rather have Tide of Progress anyway. The frigate variant can theoretically hand over five unblockable damage that way, albeit a 1/1024 chance. (For math nerds too lazy to find a decimal, that's barely less than a tenth of a percentage point.) I think it should provisionally be one die only, and costed that way, and we can experiment with how that actually plays. If it proves to be useless, we can buff it later.
Cool, I'll rewrite it when I get home from work. By the way, a happy medium may be to specify red crits only (so 3 potential unavoidable damage, only slightly better than a double hit + 2 accuracies and almost as unlikely).
One further thing keeping this ability in check is that it makes accuracy results fairly useless. So what if you can't spend a brace/evade? The damage is, quite literally, already done. Which I suppose makes SW-7 Ions a great synergetic upgrade - not a bad thing.