Its true that Brompton almost didn't innovate since the original design of Andrew Ritchie which was a real braking thru innovation since decades later its still the smallest folding bike on the market (yes Dahon Curl is maybe slightly smaller, but the difference is marginal and the Curl designed is derived from the Andrew Ritchie design).

The T-line is for me no design innovation, just a material upgrade and the 4s derailleur is just ridiculous.

But the Asian clones are also no innovations, they even copy the drawbacks of the Brompton (the bigger wheelbase is not an innovation and not needed to make a more stable bike, other folding bikes with the same wheelbase as the Brompton are more stable).

And Litepro is probably the worse, they only copy other manufacturers products (not only Brompton) selling cheap low quality copies, they do not innovate at all.

Nor Brompton nor the copycat brands made folding bike design progress (excepted for the much lower weight with the T-line but the organized shortage commercial strategy is a shame).