I don't think anyone needs to be a genius to work out which large city is located to the east of Reading... whether they have just started commuting or not and, as a result, where all the trains are going to end up. People aren't stupid. They can work out for themselves what's going on, they talk to fellow commuters, etc.
I doubt 10 and 11 could handle any more trains - they're already busy enough and moving trains across from the relief line would cause conflicts with westbound relief line services, freights heading to the Berks & Hants, etc - the whole point of rebuilding Reading station and adding the flyover and altering the junctions to the west was to remove conflicts.
In addition, switching the Didcot limited-stop 387 services to/from the main lines at Maidenhead or other places to the east makes the best use of the capacity available on the reliefs and allows trains arriving from the London direction to be sorted out well to the east of Reading.
I've said it before, so I'll say it again - is it so hard for all the people here with 'solutions' to just wait and see what impact the introduction of the 387s and 800s, with their extra seats, the new GWR timetable in 12 months' time and Crossrail reaching Reading in December 2019 have on the situation?
All that adds up to a huge increase in capacity for the Thames Valley, even before you get to the likely changes to travel habits that Crossrail will permit, by offering direct access to central London and the City. It may just turn out that they do the trick all by themselves, without barriers, armies of staff policing commuters, etc, etc, etc...
As we can see, reddragon's journey habits have already been changed just by the first phase of 387 operation west of Maidenhead.