The solution is simple math, for computers to base their time on TAI, the time zone conversion changes from "UTC + local timezone offset", to "TAI + UTC offset + local timezone offset" and we reap the rewards of drastically simpler software at the core of our systems.
TAI is defined like UNIX time, as a notation of the progression of proper time. It is the primary reference by which we build all other times, UTC is a humanist overlay on TAI to maintain norms, since we need an approximate terrestrial solar time for sanity purposes.
If the math changes to TAI as the "base storage representation" for time stamps and reference time internally, then the math becomes immediately sane, since TAI can be relied on as a direct sequence of mathematically related linear time without lookup tables or other crap. Move the crap "up the stack" to where it doesn't cause issues like these we see every time things need a leap second.