Brompton’s stance is that non electric bikes cannot be retrofitted. There should, in theory, be design considerations to make e-bikes more robust than non e-bike models due to the different forces placed on the bike (especially with a front wheel motor).
In practicality, one could fit a non e Brompton with the kit and it would work. It would void any warranties, but no reason it wouldn’t work mechanically.
Electric Bromptons have a strengthened fork and extra holes in the bottom bracket for the torque sensor. I'm sure you could make it work but it's not a simple bolt-on replacement.
Brompton’s stance is that non electric bikes cannot be retrofitted. There should, in theory, be design considerations to make e-bikes more robust than non e-bike models due to the different forces placed on the bike (especially with a front wheel motor).
In practicality, one could fit a non e Brompton with the kit and it would work. It would void any warranties, but no reason it wouldn’t work mechanically.