Is the rotation really fair?
Among people available on each day, the one with the fewest turns so far is chosen first, so the difference is at most one turn (people with many days off get fewer).
Different headcount on some days?
Edit the table before printing, or split the period and generate twice.
Include weekends or exclude holidays?
Tick Saturday/Sunday to include weekends. For holidays, split the period rather than writing days off for everyone.
Does the same URL give the same roster?
Yes. The URL contains the random seed, so everyone who opens it sees the same table.