There are already many transcribers available, but none of them correspond to description of Black Speech mode at Amanye Tenceli or do not have it at all. Glǽmscribe is close to perfection, but for some reason it uses Quenya mode for diphtongs in Black Speech.
Currently, BSSScribe supports only legacy Daniel Smith's encoding for these reasons:
Limited support for Unicode CSUR encoding was added on 2022-09-30, currently with only 3 fonts.
Please note, that text for transcription should be spelled correctly according to chosen language. Any inappropriate characters will be encoded wrong or skipped. For example, this tool will not convert Qenya “k” to Late Quenya “c”, so the result with Qenya may be wrong.