No ADS as a Beginner?

Hi All!

I am seeing some surprising results and was hoping to just get some reassurance and maybe context?

Physical Context:
Male, 27 years old
No max heart rate test but call it 193 based on the 220-age rule

Training Background: I have been primarily climbing, and occasionally downhill skiing and hiking for several years. I have trained for climbing (I do route climbing, so perhaps more aerobically fit than a boulderer), and have weightrained for close to 8 years minus a brief hiatus during the COVID lockdown. I have NEVER trained aerobically to the degree that I have been for the last month or so, but have logged say 6-8 hours a week for the last 2 years on average through these other activities.

Fast forward to my AeT and AnT results. I am training for Ski touring.

AeT: took several drift tests over a couple of weeks. Got just under 3% decoupling at 145bpm, negative (i.e. second half HR average lower than first) at 150bpm, and 2.5% at 155bpm. All walking 15% incline treadmill. The last test (155bpm) felt moderately difficult but was still easy nasal breathing, could keep up a conversation with pauses for breath. I know from recent experience that working over 160bpm feels reasonably difficult.

AnT: Got an average of 172bpm on a stair master for 30min. Felt challenging but not absolutely desperate, although when I tried bumping the pace by one about 15min into the test, it quickly became clear that I would crash and burn at the higher pace (HR spiked to >180), so I feel like I was at least near the fastest pace I could do the test at.

At face value, it looks like I do not have ADS, and a seemingly high AeT, despite having essentially no history of dedicated aerobic training. Am I missing something here?