When updating to 126.96.36.199 I noticed health bar animation no longer updates quickly (although the color still does). I have "Internal Timers and Updates" set to More CPU, but it doesn't make a difference. Today I updated to 188.8.131.52 and see the same delayed bars issue persists.
The timer that controls the fluid bars and aggro was changed to go to sleep when nothing is happening. this can be up to 1sec before it wakes.
With aggro the timer is activated if the next check is greater than 1/10sec away (will change this based on Internal Timers and Updates) but this wake up now call was missed with fluid bars, fixed.
Also are you using HealBot_fastHealth or waiting for the health event?, I noticed a delay in the health update that suggests your waiting for the blizzard api event.
In the next version fastHealth will be faster, especially when Internal Timers and Updates is set to use more CPU.
Following up on this, the 184.108.40.206 release fixed the delayed bars issue. I ended up turning off use fluid bars and the results are HB's bars are just as responsive as ElvUI/Default UI.
Thank you for the update Strife