Applying that on its own would let an otherwise-loser
churn a double ko to keep the game going forever.
To avoid such churning, there are two good fixes I see:
(S) Spights superko rules Spight Rules at Sensei's Library , or something similar
or
(L) a long-cycle rule, in addition to (not instead of) the basic ko rule:
Repetitions of the 3-tuple
board coloring , player who’s turn it is , the 0 or 1
intersections that are banned by the basic ko rule
such that in the cycle [[the players passed different number of times]
or [the players [played captures that would’ve been illegal if
pass-pass didn’t lift basic ko bans] different numbers of times]]
end the game: If the players passed different numbers of times in the cycle, then
whoever passed more in it wins. If in the cycle, the players passed the same number of times
but [played captures that would’ve been illegal if pass-pass didn’t lift basic ko bans]
different numbers of times, then whoever played fewer such captures in the cycle wins.
(The latter is at least an approximation of, and maybe even equivalent to,
there are N 0 pt ban lifting moves, where N is finite but otherwise sufficiently large.)