I had a look at the petition this morning, and also a look at the application.
There are loads of comments registered, but the vast majority only talk about the importance of 414 in their life. Admirable, but a waste of time in planning world.
Planners can only consider aspects of non-compliance. If people want to object objectively, then they need to target defined areas of planning law.
The applicants have clearly consulted with planners as evidenced by the D&A. The case officer can't see obvious non compliance with legislation.
I'm sure there is a policy about affecting the local area, implemented to stop massive industrial units etc in residental areas.
There have been a few comments on the database about affecting the local area. Tbh I don't think objectors stand a chance, simply as the planners cannot refuse an owner's application without good reason, but for a targeted approach then that is where I'd start.