Adrian wrote:

Chesham to Chigwell is 2 hrs 2 mins (with walking speed set to slow).

For these types of journeys, the waiting time is also important. At a
gated station, you touch in, then wait - at somewhere in the far-flung
reaches of the Tube like Amersham, you could potentially wait 20 minutes
for a train (similarly at Baker Street in the other direction).

Chesham-to-Chigwell would include a wait to change from the Chesham
Shuttle
at Chalfont & Latimer, too - apart from the small number of thru trains
per
day, at peak times.

Indeed. Also it's often difficult to get an Aldate-Amersham through service
and so you'd be doing all the changing there as well. I presume the on the
move travel time incorporates a through service at Woodford?

Are the gates able to be flexible and match the distance between barriers
with the time between swiping in?