I think we've misunderstood each other here. I'm not talking about the Gaelic language, which today has a standardized script and thus uses its own writing system with Latin letters, recognized by all speakers, to express precisely those sounds that cannot actually be expressed with Latin letters. I don't mean the letter combination that we accept as universally valid in textbooks and on the internet. I'm talking about the fact that in the Middle Ages a group of people tried to write down the sounds they couldn't express with the Latin alphabet, in order to write down their language for which there was no written form. The language example that I attached yesterday simply shows how complex the Celtic language varieties are and how difficult it is to represent this with the Latin alphabet.
To represent the sounds of Celtic languages in the Latin alphabet, a standardized letter arrangement is still required today. That's exactly what I meant by "still not compatible"
I'm attaching a few more "google hits" regarding Celtic language and Latin alphabet
"the Celtic languages faced problems with the Latin script, as the Celts did not have their own widely used writing system, and the Latin script they used for inscriptions such as coins or maps was only partially suited to their specific sounds and grammar. Problems arose because the Latin script could not represent all Celtic phonemes, which led to differences in transcription and hampered readability and the development of a standardized orthography."
"The Latin script was not ideal for representing the specific sounds and phonemes of Celtic languages. Therefore, adjustments had to be made."
"Problems between Gaelic languages and the Latin script arise because the Latin alphabet was not designed for the phonetic characteristics of Gaelic languages, leading to inaccurate representations of the language. This is due to the fact that Gaelic languages already had a complex structure when attempts were made to write them with Latin letters, and certain sounds and grammatical forms do not occur in Latin."
To represent the sounds of Celtic languages in the Latin alphabet, a standardized letter arrangement is still required today. That's exactly what I meant by "still not compatible"
I'm attaching a few more "google hits" regarding Celtic language and Latin alphabet
"the Celtic languages faced problems with the Latin script, as the Celts did not have their own widely used writing system, and the Latin script they used for inscriptions such as coins or maps was only partially suited to their specific sounds and grammar. Problems arose because the Latin script could not represent all Celtic phonemes, which led to differences in transcription and hampered readability and the development of a standardized orthography."
"The Latin script was not ideal for representing the specific sounds and phonemes of Celtic languages. Therefore, adjustments had to be made."
"Problems between Gaelic languages and the Latin script arise because the Latin alphabet was not designed for the phonetic characteristics of Gaelic languages, leading to inaccurate representations of the language. This is due to the fact that Gaelic languages already had a complex structure when attempts were made to write them with Latin letters, and certain sounds and grammatical forms do not occur in Latin."