I have long proponed that it is quicker to walk from the T4 Flagship Lounge and go out landside (stay at the departures level) before going back through TBIT security to the lounges than take the bus.
Other than that there is no point fronting for the (now) gate 45 bus other than 25 minutes after or 5 minute before the hour.
So, the shuttle only operates every 30 minutes then?
Feel sorry for those that have just missed one and have to stand in line for 30 minutes at T4 for the next one...