I considered posting this as a separate topic because, although it follows the same general line of thought as the original post, it shifts the focus quite significantly. In the end, I decided to post it here. (If the discussion grows substantially and it seems worthwhile as an independent topic, I can request that it be split later.)
First of all, I would like to make it clear that I am not trying to argue against OSM’s principles or oppose anyone else’s opinion. Rather, while respecting the existing consensus and practices within OSM, I would simply like to suggest that the current consensus and principles may also be interpreted in the following way.
As I understand it, OSM gives the highest priority to the on-the-ground principle—that is, reflecting what actually exists or is actually used in the real world.
OSM also already provides a dedicated tag (“official_name”) for recording official names.
More importantly, for the region currently under discussion, there has historically been little interaction with Korea, so there is no established or widely accepted Korean pronunciation of those place names.
In such cases, I think it is reasonable to regard the pronunciation that Korean speakers can naturally pronounce while remaining as close as possible to the actual local pronunciation as the ordinary Korean name. (For example, I am fairly confident that Korean speakers who actually live there would tend to follow the real pronunciation rather than a formal transcription rule.)
As an additional option, “alt_name:ko” could also be used. However, I think it would be most useful in cases where a conventional Korean name that differs from the actual pronunciation is already well established, allowing a pronunciation closer to the original to be recorded as an alternative.
Looking ahead to future applications and increased automation, I also think it would be beneficial to encourage the use of the official “name:pronunciation” key for recording the actual pronunciation in the International Phonetic Alphabet (IPA).
As I understand it, this key can be used by software when converting names into spoken audio.
In addition, where the pronunciation of a name in a particular language differs significantly from the actual pronunciation, the “name:*-fonipa” keys may also be a useful solution. For example, the capital of Korea, “Seoul”, could be recorded as “name:pronunciation=[sʌɯl]'” and “name:ja-fonipa=[soɯɾɯ]”. (Here, “name:ja-fonipa” represents the IPA pronunciation of the Japanese rendering of the place name as it is actually pronounced by Japanese speakers.)
Of course, before discussing how OSM’s principles should be interpreted, one could also argue that, in order to minimize confusion for map users, it is more important to maintain a consistent principle and a consistent naming convention. I hope this aspect will also continue to be discussed.