It’s a minefield isn’t it boys?
There’s open mould bikes from shit QC OEM houses.
Open mould bikes from good QC OEM houses.
Open mould bikes from OEMs who have on- site QC from a brand’s representatives.
Open mould bikes made to modified spec for one brand only.
Territory limited moulds where you’ve shouldered part of the dev cost and get a region exclusive.
Closed mould bikes with all of the above options.
Old open moulds tend to get passed around, literally. A company might use them for a few years, then redo the mould and sell the old ones off to another OEM. These are your ‘no brand’ eBay bikes. When you see the same frame shape from loads of different sources on all the auction sites – steer clear!