From past experience KwikFit are kept on a tight lead with Motability and can’t replace tyres too early , they get spot checks at depots by Motability to check tyres not replaced with more tread than the agreed 2mm.
We has a VW transporter a few years back with around 2.6mm tread left ,KwikFit twice said come back when on 2mm, manager took me to one side and said book tyres on the mobile site when they come to you home..tyre depth don’t get checked on mobile service !
I’ve always liked tyres fitted at home both on our Motability van and my personal vehicle all done at home ..it’s just more convenient as a carer ????