My daughter is dyslexic and is in her second year at uni. The DSA assessment took about 45 minutes if I remember correctly. It was basically just an informal chat about her way of studying and the things that would make life easier for her. Like you she has visual stress associated with the dyslexia so can start the week with 10/10 vision but be below 7/10 at the end of the week due to the amount of reading and the concentration that it requires for her.
The DSA assessor proposed all kinds of software and demonstrated the capabilities of each during the assessment. We then accepted or rejected the proposal. We were also allowed to request things that we used already at home and would like at uni.
So for us we were advised to take a voice to text application as well as a text to voice which would allow my daughter to listen to her lecture notes rather than reading them if her eyes really were too tired. In addition we requested an A3 colour printer for mind mapping. We had to pay the difference between the basic printer and the model requested but we were allowed it, so I would be surprised if they refused your reading pen even though they probably have better things to offer you.