I've had five Bromptons to date, four of them used. The folding pedal bearing is always on the way out when I buy a used one, even if the bike has obviously done a very low mileage. Take off the pedal and feel the bearing properly: it will usually be notchy even if there is no play in it yet.
You wanted solutions, so here is mine. I file off the retaining lip and press in a new 62032RS bearing with Loctite 603. It is a very tight fit and the Loctite needs 200 deg C heat to release it, so the pedal won't fall off. Use a good SKF bearing and it'll go longer than the original (one that I did in 2009 is still being ridden by its new owner). This doesn't address the issue of the single row bearing but the OEM bearings I've removed have been noticeably cheap ones, saving a quid on a £40 component.
I do see signs that Brompton are slowly beginning to fit better components, like brakes and rims. The current 1/2 speed freehub is quite nice, too. There's still too much typically British engineering on the bike, though. I persist with them because I understand how to fix or rebuild them, I can still buy MOST spare parts and they still fold smaller than other bikes.
I take an objective view of these things. I'm not a fanboy.