SAT2 operates partly on two separate levels...re-model?.
Outline permission has existed for many years though for a take up of SAT4.
With the original concept as it stands I doubt any TTS engineering is already in place regarding SAT4 as the BAA as it then was ran into large problems with the local Council in not providing TTS to SAT3 in the plans with the Council stating the walk as planned would be too long for passengers.It was all about costings between BAA/UDC & in the end UDC relented when BAA compromised/provided for & installed the travellator /moving walkway system for part distance out to SAT3.
It was always thought & said but not confirmed absolutely though that in the original construction & development on the South Side future proofing was indeed provided with foundations built & covered for the modular expansion concept for which STN was the forerunner.
Stands to the east of SAT 3 built later were overconstructed to provide for the heaviest widebody as an example.
I think the new arrivals terminal puts it right in front of SAT3...A SAT 4 will be farther out to the east & will require some provision of automation/people moving undoubtedly.
Very interesting regarding Jet2 & perhaps unsurprising as they work up the Stansted base & their excellent relationship with MAG.