Even if that's the case, it's much easier to change trains by just waiting on the same platform than it is to trek across Paddington and go down 2 sets of escalators to the low level station. If there is an EL train going to Shenfield then get on that and go to any of the 'core' stations between Paddington and Whitechapel, get off, wait like 3 minutes and the next Abbey wood train will come and get that. If it's a long wait for any EL train then get the next HEX and get off at T2,3 and wait on that platform for an Abbey Wood EL train coming from T4.