The docs for cli_progress_step() indicate that we can pass arguments to cli_progress_bar() via ..., but this is not true for clear, which produces an error if set:

cli::cli_progress_step("msg", clear = TRUE)

# Error in cli_progress_bar(type = "custom", format = format, format_done = format_done,  :
#   formal argument "clear" matched by multiple actual arguments

As far as I understand, it makes sense that clear = FALSE should always be set for cli_progress_step(), but then we should silently drop it instead of failing.