10 years at 25 degrees is far, far, far beyond what your mobile...

10 years at 25 degrees is far, far, far beyond what your mobile phone needs. Who keeps a mobile phone switched off for 10 years planning to keep data on it long-term? Nobody I know. Back in 2015, the figures for data retention in the flash that was, and still is, being used in phones was 1 year at room temperature. (https://en.wikipedia.org/wiki/Flash_memory#Archival_or_long-term_storage) I don't know why you would say 10x that figure is "not good enough" when nobody is having a problem with it right now, and it is really just a proven minimum at this stage for weebit, not a maximum.