I think it is more to the point for there to be a way to maintain the unset time while changing the value. This should be done with another -switch in the /set command. Example:
/set %A 1 => Permanent
/set -u60 %A 2 => Unsets after 60s
<17s pass>
/set -v %A 3 => Unsets after 43s (remaining time from -u60 switch)
%A = 4 => Becomes permanent again
Also, there should be a property added to $var to retrieve the time remaining in a /set -u## var. That way, you could modify the time based on how much remains. Example:
//echo -a $var(%A).unset => echos 12
/set %A $+(-u,$calc($var(%A).unset * 2)) 5 => Multiplies the time remaining by 2)
-genius_at_work
