then you are managing anti-dive well already. well done.
without the benefit/capability of turning the THC off and on via gcode in slow feedrate conditions, I believe anti-dive trigger is a combination of both speed (deceleration) and ARC [not] OK signal (aka arc on pilot).
I built an anti-dive circuit for my controller and THC, it triggers based on feedrate deceleration, when actual feedrate < 94% of programmed value, and releases when feedrate > 95% of programmed value during acceleration. It works by blocking/unblocking the THC STEP signal to the Z motor. It also allows for dynamic THC ON/OFF via gcode command, again by blocking/unblocking the THC STEP signal. It’s built to work with an autonomous THC such as Proma THC SD.
I found during testing that my THC moves Z 0.1mm / 1volt deviation of arc voltage. I also discovered that there is a significant difference (improvement) in activating anti-dive at speed threshold of <94% of feedrate vs. waiting until <84%.
You can read about my trials and tribulations here: Proma THC SD or 150 discussion - (warning: bring coffee)
and here: GRBL Plasma w THC, Torch Touchoff, and Rotary - #40 by bLouChip (read prior posts also)
The ant-dive circuit diagram is available in those threads also, and gcode described in the comments of the scpost.