[l_t]

I think of this as an optimization kind of problem. The word "efficiency" itself is only meaningful in context of what's being made more efficient.

A system could be "more efficient at becoming stable," for example.

But if by "efficiency" we limit ourselves to mean "the time-cost of a set of actions," (as in the most efficient path is the one that takes the least time), we quickly encounter problems with maximizing usage of time and how that conflicts with unexpected work, which leads to the anti-stability you mentioned.

The way I think about it is that a 100% time-efficient process has zero time-flexibility. If you want to gain time-flexibility (e.g. the ability to pivot, or to work on different things too, or to introduce error bars to your calculations), you lose time-efficiency.