Hello,
According to the testing done by another staff member, you can track the amount of damage you deal based upon the total health of each node. They are as follows.
10k, 50k, 100k, 300k, 800k, 1.2M, 5M, 8M, 12M.
Once the last node is passed, you return to the full health bar. At that point, you can calculate the damage done by doing the following:

Max health - Current Health + 27,460,000

Hope this helps!

That would have been my preference as well. People asked for UI updates for the system, but the result was...less than satisfactory in my opinion. If you'd like, I can submit a suggestion from you that the overall damage be directly displayed on the UI?