Couldn’t find a T with inspection hole at Screwfix but did manage to procure a space gun to drill for the waste pipe.
View attachment 422388
First I bought the core bit and sds adaptor.
Then went back and bought the pilot drill that didn’t come with the core bit.
Also had to get a comedy length 8mm masonry bit to pre drill from inside. Oh and it knocked off a big chunk of the brick.
Gave up core drilling after about ten minutes as I’d only gone through about half a brick and my arm was falling off.