So interchange from deep tube to sub-surface will mean a longer walk
than the original (pre-redevelopment) route?

It's temporary while the present stairs / underpass are refurbished and
brought within the ticketing area.


Do you have a date for this "eventual" change? Is it part of the
current project or a "nice-to-have" feature for the indefinite future?

No dates have been published but yes, it *is* part of the current
project. My guess is that we should see it in service is about six
months.