A preview of non-calculated hash (like all Fs) could be shown to avoid wasting time calculating undesired hashes.
So it would be an insert option that adds the hash; including separation, prefix and suffix. In fact, the add option has enought space to fit it:

Any algorithym that returns a short string would be a must: CRC32, Adler-32... and others like MD5 or SHA1 are also an option to be added there.