kpr I did not find exact way to measure it. But I find out that sometimes there is drop of connection. You cannot rely on this feedback in your control loop, it may cause you damage. Comparing Sonoff vs. Shelly products, the shelly have more fluent and faster response.

kpr Yes. After while the temperature in tent is stabilized and higher. Sometimes I open part of doors to ventilate air out, to keep air temperature 40-45°C. Because you heating not only printer and printed stuff, but also every electronics of 3D printer. Especially Chinese AC-DC power supplies wont like work in hot air ... it can lead to failure. Most benefit for printing is that you reduce humidity, you have stable temperature inside, you have no wind flow and significantly reduce "everywhere existing" dust.

kpr Yes, not single use battery, but recharging battery. Is not easily accessible, just with tools and screwdriver.

kpr Yes can be used. eSUN box have small heater inside, but for moisture removal there is not TEC (peltier) device. You should put Silicagel bag into box. During hours, days, the moisture decreases. After some time, you should renew Silicagel bags (i.e. in oven or fruit dryer). With this way I dried 5-year old PLA stored in air, then 9-hour prints were nice.

kpr And where exactly is the drawing? :-) Please attach it to photos in purchase item...