It seems that even Mobiky doesn't carry your weight

Mobiky Genius has maximum load of 240 lbs.
Adjustable height allows up to 6' tall

The Brompton is designed for loads not exceeding 110kg (rider)
plus 20kg (luggage) so that one 242lb could maybe not carry you either?

I have the same problem as you have. I'm
194cm which if I remember is 6' 4" or so.
And my weight is around 95 kg or 210lb
I use an old Microbike just now which could
handle 110kg if new but now when the plastic
wheels are old they easily brittle the designer told me.

but I long for to buy something else. The bike I like the best
have 85kg as highest weight. Carryme from Pacific Cycles Taiwan.