I appreciate that its necessary to adjust the clocks to celestial bodies as appropriate. But why do it all at once, and suffer from the aftereffects.
When a leap second WOULD have been declared, have the NTP stratum-1 servers bias things a bit until the -1 and astro-time match, and let the world catch up over the next few hours/days (one tiny increment at a time).
No software glitches. Tiny differences between systems, but we always have those anyway.
Astronomer's and other's that really care, use -0 time adjusted directly