The university publishes admissions data, which you can find here:
https://www.undergraduate.study.cam.ac.uk/apply/statistics which includes a section on application from those with declared disabilities. However bear in mind the numbers of applicants who declare disabilities are quite small compared, and not all who have a disability will declare it, so do take this data with a grain of salt.
Obviously disabilities including specific learning disabilities are protected by law, and it would be very bad for the university if they were found to be discriminating against applicants on the basis of protected characteristics. As such most, if not all, staff at the university have mandatory equality and diversity training which is pretty regularly reviewed to ensure it is up to date and relevant. It's also repeated (I believe yearly for admin staff such as myself at least), and in the most recent session I had they did specifically cover issues to do with unconscious/implicit bias. To my knowledge admissions staff have further specialised training for their role through the central uni administration and I imagine the individual colleges might also arrange training as they see fit.
Cambridge is, in my experience as an employee, very sensitive to such issues and works pretty hard to try an support them well. I imagine for students this is even more true, at least in terms of the central administration, as they have a dedicated disability resources centre and student counselling section that may be related to issues which require students to get extra time in exams. Additionally the overall administration (centrally at least) is very student focused (which may or may not be unsurprising depending on your perspective). Individual college arrangements may vary though.
Overall I think of all universities, Cambridge is one of the ones that is
least likely to discriminate against applicants who have extra time in exams. There is a lot of focus on accessibility and widening participation in terms of admissions and the student body, and numbers of students requiring extra time in exams at Cambridge has, to my understanding, been increasing in recent years. They are also very aware as an institution of the amount of publicity and public scrutiny they receive, and they are very careful to ensure their reputation is upheld. While this may not be the best reason to ensure they treat such matters with the appropriate care and sensitivity, it does mean they are at least!