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How is extra exam time for disability accommodation perceived by professors, especially potential reference letter writers?

Some students with what is considered as academic disabilities receive 30 minutes of additional time for every hour of exam, which is a factor of 1.5 to the exam time.

How is this perceived by professors? Might some of them think that these students get an edge or advantage over other students unfairly?

If a student is looking forward to requesting a reference for grad school from a certain professor, would it generally be better for him/her not to request exam extensions for this professor's course?