I created temperature thread.
I agree totally with shoog above, there is no throttling I guess, but for long term view, I wouldnt let run these device higher than, lets say 50-53 in idle… You can feel temperature even just been around, when temps are 53 and higher.
Personally, I have 8-9y boxes, running 38-48, nothing wrong with them works still as new (Rpi, Rpi2, later C2 but Ive got those only like 1y or such). So I get this as good rule of thumb, if temp is between 35-55 (55 is max, and only when under load, like 4K movie etc.), devices should be fine and live long.
Dont have long experience with cheap chinese Androids, but compare with Odroid/Khadas SoC, I think they could be in similiar long span, if user take care about heat - if you have screwdiver, drilling machine, solder, tweezer, knife etc. at home,using it reguralrly, those boxes can provide great value for much cheaper price, as you are able to easilly improve it practically free.
If not, I would recommend a bit pricier solution with better cooling out of the box. AFAIK, I didnt hear about PROOVED cheap chinese unknown with cool temperatures and PROOVED justOS for them. I just jump into S905X3 boat, as they seems to be more likely wide supported within (future) CE. 912 could be cooler but dont have deeper experience how well are supported within CE.
As I wrote in that topic, feel free to all with some nice temperature test @other device share with community in temperature topic (with enough description,it would be great to have utilized summary, and not 20posts about the same device in different conditions
P.S.: I dont claim that X96 cannot be operable in 60°C by 6 years… I just dont have that experience and like to treat my things nicelly in general