Relatedly (though less important), the example datasets don't print as tibbles by default. If you follow the instructions in usethis::use_tibble(), you could support printing it as a tibble even when the tibble/dplyr packages aren't loaded. The additional advantage of this is that you could get rid of most of the uses of head() in the README, making your examples more concise and focused on your use case.
Relatedly (though less important), the example datasets don't print as tibbles by default. If you follow the instructions in usethis::use_tibble(), you could support printing it as a tibble even when the tibble/dplyr packages aren't loaded. The additional advantage of this is that you could get rid of most of the uses of head() in the README, making your examples more concise and focused on your use case.