See Senn reference and pdf here: https://discourse.datamethods.org/t/bbr-session-7-study-design-and-crossover-experiment-example/2780

From Stephen Senn 2023-10-19:
Such (n=400) cross-over trials are very rare. During my time in pharma, I struggled to persuade people to run cross-over trials with as many as 24 subjects. I ran many during my time in pharma. The largest was MTA/02 which had about 160 patients and seven treatments studied in five periods using 21 sequences. The trial is described here https://www.slideshare.net/StephenSenn1/the-story-of-mta-02 and here http://www.senns.uk/SELIPATI.pdf and the data are available here http://www.senns.uk/Data/SJS%20Datasets.htm under Incomplete Block Cross-over