Split-ticketing in London with Contactless

An interesting anomaly came to my attention, whereby someone planned a journey from Brixton to Reading starting at 0900. Oyster is not valid beyond West Drayton, but using Contactless the through (peak) single is £29.20.

However, if he used Contactless just to Paddington (£3.20), by then it would be post-0930, so an Off-Peak fare of only £11.30 would apply for the second leg - a total of only £14.50.

No! This works all over the country with paper split-ticketing, but with Contactless in London when you change at Paddington it gives you 40 minutes to change trains without charging each leg separately.

That normally benefits, but not here! It would instead ensure the whole journey was still charged £29.20 - unless you waited back over 40 minutes to ensure that the second leg was counted as a fresh journey.

The way round it is to use two different bank cards (or Oyster just for the first leg), although you would then lose the daily cap. It takes some pondering.