A question we (a group from our club) always ask at exhibitions is - why not print it in English too?
I think this case is actually a good example of why printing it in English is not the answer. It would be trivial to transcribe the symbol TEMPO into the word "temporarily". However the subtlety and difficulty is in the interpretation of the word, however written, which means "for periods not exceeding 1 hour duration in each instance, and not exceeding half of the period in aggregate". If you write that in full every time you end up with information that is so long it's impossible to digest. If you don't, you might as well write "TEMPO".