As a local I would very much like to see a Chingford - Stratford service. The trick will be how you schedule it without damaging the service to Liv St, the ECS runs from Chingford into Liv St and provide something moderately sensible in terms of headways at Lea Bridge and into / out of
As another local I'd also like to see this too. I live in North Chingford and often travel down to Westfield but get slightly exasperated that there's no quick and easy way of doing the journey. I can go via Hackney or via Tottenham Hale, but if I don't make good connections the journey's not much quicker than doing the long slog on the 97. In fact, from the Chingford station area even just a 179 and the Central line can give the other options a run for their money I find.
Based on current infrastructure, I think the quickest feasible route from Chingford to Stratford would be via a frequent, reliable bus service to Ponders End station (doesn't take long on a 313, when one bothers to turn up) and then the train from there. Considering the line speed of the WAML, I don't think that'd take inordinately longer than a train from Chingford via the hall farm curve. Sadly Ponders End station currently only sees direct trains to Stratford on Sundays though.