The clones are available online and can be shipped to Europe.

I think that they aren't sold in bike shops because there is no distributor nor anybody else that will provide the legal 2 years warranty nor provide any after sale support.

Its the same as for many Chinese ebikes that are also only available online with a main difference that the market for folding bikes is much smaller that for ebikes.

I also think that for tri-fold, Brompton is very strong in Europe and people prefer to buy the real one than a clone that with the legal warranty and an after sale support will be not be much cheaper.

now, its interesting to see that two specialists of bi-fold folding bikes, Dahon and Fnhon, presented tri-folds folding bikes with for Dahon the selling proposition that tri-fold folds smaller than bi-fold that Dahon more or less invented and advocated during decades.