Just a remark: these 20" trifold aren't Brompton G-line copies, they are only 16" Brompton copies enlarged to fit 20" wheels with many weak points of the 16" Brompton including 35mm max tire width (instead of 55mm for the G-line) and are nevertheless bigger folded than the G-line.
They were already on the market long before the G-line was even announced.

Glad to help.

Regarding gear range, yeah 33 gear inches is not low enough for hills, I need 21 for the hills here, moderate and not too long. For heavy touring with mountains, some have recommended as low as 15, and I can get there with a wider cassette. 85 as a high matches my setup, will let me pedal down mild grades, and steeper down I just coast. 21-85 is 400%, I think is minimum, and not too hard to obtain.

Thanks Jipe, valuable details as always.