Support LongLong - or BIGINT - natively in Access 365 just like Excel 365.
BIGINT needs to be turned on in Access 365 and 2016. LongLong (2^64) - 1 is simply another data type available natively in Excel 365. This should be available in 64-bit versions of all Office applications VBA as well as the tables in Access.
BigInt support already exists as an option in Access 2016/2019/365.
However, once switched on, the database cannot be opened in earlier versions of Access.
Better to leave it as an optional item