I want to be clear. Target 02:20 put me, it was my idea, not a JS Coach.
When I hired coach, I showed him all my training logs since january 2020 + my cycling 3 years as a amateur. My idea was simple, I decided to continue endurance sport, but with my seaman job (4month on/off) it is very hard to continue as a cyclist, so I moved to running as it easier to train even while I am onboard. So first step: run good solid base: 4-8 months without workouts, than second step: hire any coach and continue with workouts, target is 1-3 races per year (aka Lidyard system).
Regarding treadmill: it was calibrated properly and by all oxygen consumption theory, all ever existing calculators effort on treadmill was harder than on land with compared to display speed as I ran with 2-3% gradient constantly, but I found out when touch downed on land, that on treadmill little different muscles were working than on land, and different way of working (downhill, contract, amortization by quads are not working on treadmill, strides, etc.)
As soon adaptation will be completed (approx. 7 days more) will continue training with workouts, track, etc. For the november is planned 10K TT.
Yesterday I tried 2x400m at 5K pace: 02:48-02:55 I can hold, even breezing was easier than on treadmill. On treadmill, last 20x400 it was at 03:00. It is earlier to make final conclusion, lets wait 1 week and first workouts: 5K, LT etc before any decision.
If somebody had long usage treadmill experience and than he jumped on land, I would with pleasure will listen his opinion and feelings.
My personal computed model forecast shows, that since last 4 days running on land avg heart rate at easy pace is gone down 2-3 beats, it is quite fast, meaning that I have already fast paces inside of my body, just need some time to adapt. Everything can happen, of course, but up to now adaptation is going positive: avg heart drops, avg pace rise with favorable speed.