TRV settings in eWeLink?

Was just reading the manual before buying some valves for my last few un-smart radiators and couldn’t see an offset function? Or a range set? My current TRV (both types) have both and one of them is really old. I’m guessing they are there but in the app and not easily accessible on the device but want to check first? I have 3 radiators in a bit for AirBnB (which is why I don’t have Smart Valves already) and it would be a real pain to explain to guests the number is wrong and airBnB people do all sorts of things that are weird (like turning it up to 50°C).

Found.a YouTube video and paused it to see the settings in the app. Saw that offset can be set. Didn’t see a minimum/maximum though: guess that isn’t possible? Also is there a quick way to set it off/on? On my Moes valves the switch doesn’t seem to do much but I can turn on “eco” or holiday modes/off. Is there an equivalent somewhere? Also I’m planning on putting them in Private AirBnB rooms that I can’t enter all the time: Will I get battery warnings and if it runs out of battery power does it default to open or closed?