For Spine, there is the option to show the count of dead Bloods. I turned that on for our first attempts at Heroic Spine last night. I can't be more specific than this, but when I moved the Amalgamation over to the puddles, it was often able to reach 9 stacks before the addon was printing 9 deaths.
Is it possible there's an issue with it tracking those for deaths that occur very close together?
I was also thinking of how it might be able to automatically reduce that number, say, by subtracting n where n is the number of stacks received by an Amalgamation that then subsequently cast Nuclear Blast (might be wrong name). The issue with that might be if the Amalgamations can still soak up puddles without gaining stacks after 9. I'm not sure about that. I guess that also would only work for the tank holding the Amalgamation as finding it in the raid's targets would be very resource intensive.
As you said, there is the command to reset the global variable you're using and I do have that bound and have used it. My main concern is what appears to be an innacuracy with the death count.