@GeofCox Yes, I feel the Eurospeak or Globish (global English) approach may be better nowadays. The people I teach English to tend to interact with other non-native speakers more than with native speakers. As you noted, English is used as a lingua franca - actually, being in Italy, when I come across someone who does not know English, Italian is my lingua franca - and the way I use Italian is influenced by my native tongue. I shall correct with a caveat!
Some years ago I sat in on an EFL session led by a friend of mine - there was much confusion then amusement when they came across the phrase 'the fire alarm went off' - which of course any native speaker knows means precisely the opposite of what it says.
@GeofCox Ah, the joys of phrasal verbs and literal translation! Non native speakers detest them, understandably and avoid using them. I teach commonly used phrasal verbs and then there’s really idiomatic English! I pity those trying to get to grips with English and find it odd it’s become a lingua Franca.