How should I go about the phonetic development of Sindarin compound names?
I have encountered names like Anfang, which, as previously discussed, is formed from sɸaŋga. Therefore, you would start with ✶anda-sɸaŋga and proceed from there. Ellanto mentioned that most of these are later compounds. In that case, I should start with ✶and-ɸaŋga, which would yield the desired results. However, for names like Aegnor, which Eldamo shows as ✶aika-nār-, it's an adaptation of the Quenya mother name Aicanáro, so it makes sense to start with Old Sindarin and then move to Sindarin.
Should I even concern myself with the stages at 23 and 33, as most tend to either drop the short vowel or it vanishes at the morpheme boundaries? I'm trying to do it the proper way, primarily for my own understanding, but also for others who are interested in the process. I'd like to share this once I'm done. :) For example, Aegnor shows the progression [aikanauro] > [aikanaur] > [aiganaur] > [aignaur].