I couldn't find a similar document from BE, but as an FYI in case this might help focus your search:
In canton ZH it is only applicants
over 75 who are excused from the language requirement.
https://www.zh.ch/content/dam/zhweb/...ewilligung.pdf Bei über 75-Jährigen wird kein Sprachnachweis verlangt. Bis zu dieser Altersgrenze muss der Sprachnachweis aber den üblichen Vorgaben genügen.
Looking at the list of exceptions to the language requirement in the federal legislation (Art 77f, VZAE), I could not find a mention of an age cut off either.
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There are others on this forum who know far more than I do on the subject, hopefully one of them will come along soon with better information.