Is it safe and legitimate to use std::experimental features in a library released to the public?

Question

Suppose I'm writing a library which targets C++14-capable compilers.

In C++14, several standard library facilities were introduced as experimental, e.g. optional and filesystem.

Is it:

1. safe (for downstream developers)
2. legitimate

for me to utilize these features in my library even if only C++14 is supported? e.g. in the form

#if __cplusplus >= 201703L
#include <optional>
namespace mylib {
using std::optional;
using std::nullopt;
}
#else
static_assert(__cplusplus >= 201402L, "C++2014 is required to compile this program");
#include <experimental/optional>
namespace mylib {
using std::experimental::optional;
using std::experimental::nullopt;
}
#endif

Note: Of course, I mean in the case of downstream developers actually having to use these features themselves, not just for the case when I use them internally only with no outside exposure.