[alpe]

I agree on most of your observations.

However, please note that other tools are better suited than aeneas if one wants to align at phoneme level: gentle, Kaldi, SPPAS, etc.

aeneas' goals are covering as many languages as possible, fast computing, targeting (sub)sentence granularity (e.g., ebook-audiobook or closed captions). Phoneme-level annotation really requires more sophisticated techniques, like HMM/GMM/NN as implemented by the tools mentioned above. Yet, aeneas can be used to quickly bootstrap e.g. a manually-reviewed alignment.