I find Kwik-fit and Motability are inconsistent. My last car had run flats and they were really keen not to change them and made me get down to 2mm before they would agree to change it. Kwit-fit just said it was out of there hands and Motability would not sanction it. It also took over an hour for motability to respond.
On my current car I had a slow puncture on NSF and after they did the tyre check Kwik-fit changed the front pair at 3mm and the rear pair at 4mm all approved by Motability in less than 5 minutes.
The manager at the local Kwik-fit told me they can do MOT/Servicing on any car on the Motability fleet which may be an alternative for some. To be honest my local main dealer is not too clever and I am tempted.
SEAT Tarraco 2.0TSi 190 4Drive Excellence with Pano Roof and leather seats!