Did you start the GDL before January 2022? If not, you won’t be eligible to take the LPC route.
I have seen people get adjustments for the SQE assessments. It’s important to flag them early when you register and really push them for the specific adjustments you need. You should get extra time for the dyslexia, and also potentially get a separate assessment room for the ADHD (depending on the requirements you need).
If the firm has some flexibility, then I don’t think there is any harm in presenting your concerns about the SQE and saying you think you will be better suited to the LPC assessments though.