exercise test: where to put VT2 and lactate >4mmol/l in Garmin HR/Lth settings?

I'm trying to figure out Garmin's definition of various thresholds but am getting non the wiser. Yes, I know their website where they explain the various HR zones, but how to correlate them to an exercise test is not mentioned. I know where my VT2 is when running, and I know the point where lactate rises above 4mmol/l from a lab test (about 15bpm difference). I know that definitions vary a bit. So my question is whether anyone can say with confidence which of the two values would be the LTh as per Garmin's definition, and which would be the lower boundary of which hr zone. Also have a VT1, which would probably be at the base of another hr zone?

Thanks guys.