Renzon,
As you point out, by applying, appealing, reapplying, it is possible for institutions to avoid carrying out their responsibilities and fitting in with the local community for years. Another example of this happening is at 35 Sunderland Road.

However, if there are complaints from local residents and civic societies, Lewisham planning department and the church themselves are more likely to take account of the objections. If this doesn't work you could always take along your own banner one Sunday!