This is not an official University of Bristol template (there isn't one.) This is my own work which I started to provide a modern template for my wife's PhD thesis and I am now revisiting for my own.
The University of Bristol format requirements are not very strict or detailled so there is a lot of creative license that can be applied here. This is just my own interpretation of the requirements.
This Class is available as a template on Overleaf at https://www.overleaf.com/latex/templates/university-of-bristol-thesis-template/bkffvdgqrssf