I agree about the delay at startup on cadence sensing drives and the issue on hill starts. Also that relatively little effort is required in Turbo mode to keep things going; nevertheless some effort is still required (around 1/4 to 1/5 of total depending which torque sensed model).I'd say that my Bosch-powered Cube would do just that on the Sport or Turbo setting the instant pressure is applied to the pedals and thereafter. With CS there is a delay before the power kicks in making uphill starts trickier than with TS. There is the caveat that I am not disabled, so can't really relate to the experience.
I have suggested before that it would be helpful for torque sense models to have an option to provide power based only on pedal turning without requiring pedal pressure. This would then give the best of both worlds.
Does the Seago have a speed controller rather than a current controller? Apart from the lack of help with uphill starts I've never had issues with negotiating awkward bits with our XF07 and cadence sensor ... though negotiating does rely on the break sensors.I agree Warwick re the CS sensor. My experience on my wifes Seago is that there seems to be a slight but awkward delay in the pedal turning to the application of power. The pedals just act like a switch but there is no consideration as to how fast or slow they are turning. Also the 5 speed/power settings are too severe. This makes negotiating bollards or crossing road junctions quite difficult. If I electrify my Brompton I would want a more gradual and smooth application of the power assistance which i would hope the TS sensor and associated electronics would provide. Perhaps this is something that can only be achieved with a crank based motor system? To be fair I have not tried the Brompton Electric yet.
Torque sensors are more common on crank drive bikes, but they are available on hub drives. https://wooshbikes.co.uk/?tskit