If SWR took ASLEF to court over this, would they have a chance of winning?
At the risk of souring a good working relationship? Maybe, but is it worth it?
So they should have taken one to East Anglia, got an ASLEF rep to sign it off and see if ASLEF drivers would defy a sign off
Neither GA nor GBRf drivers will be working with these things on a daily basis so a sign-off from either of them isn't going to be worth much.
Comparisons with 720s on GA are moot as these trains are not 720s. That a significant change was made to the cab design following ASLEF feedback does not mean that they must accept
everything without being allowed any sort of feedback. Things like overly bright indicator lights or HVAC exhausts blowing directly onto your neck may sound insignificant, but if you're working with that for hours on end can become a pretty big deal.
This issue vaguely reminds me of the Class 385 saga on ScotRail a few years ago. All the initial testing was complete, but when ASLEF reps got into the cabs they noticed the fishbowl effect on the windscreens and refused the trains because of that. I recall similar "ah they just don't want those trains" comments being posted here and elsewhere on the internet, but in the end the problem was recognised and rectified. And the trains got signed off by ASLEF.
As far as I can judge the situation, ASLEF have given a list of issues with the 701s which they want to see rectified before they'll sign off on those trains. As long as that list only gets shorter as time progresses, I do not see an issue with that.