Hi Malcolm, welcome here!
I’m just up the road from you in Leicester with a Birmingham resurfacing from 2014 and a ceramic THR like yours from 2017 so I can’t comment on the simultaneous bilateral replacement recovery aspect, and I don’t think I have seen anyone else on this site mention having both done together. There are several people on SurfaceHippy who have had both hips done at the same time or a couple of days apart, initial recovery is difficult but you only have to do it once… Not sure how many of them have gone back to running. My surgeon assured me I would not break my THR so I jogged my first 5k at 6 weeks then continued with parkruns every Saturday after that. Only just started on running longer and slower this last year trying to build fitness for the mountains, cautious because the Birmingham hip is metal on metal and will eventually wear whereas the ceramic is almost indestructible (although a friend has just had one shatter, probably as a result of a small fall).
It sounds like you have done everything according to the book so should be able to run faster and further as your soft bits finish repairing – good luck at the weekend!