The time-based limit we now have is far more effective and less confusing, so simply remove this entirely. It also had some weird, unintended, effects. On the expression grammar, we would find non-minimal cost repair sequences for inputs that were on the ORTION_THRESHOLD limit (e.g. "(+++++)") because we would stop searching nodes of >= PORTION_THRESHOLD for neighbours, but still see if they were success nodes.
The time-based limit we now have is far more effective and less confusing, so simply remove this entirely. It also had some weird, unintended, effects. On the expression grammar, we would find non-minimal cost repair sequences for inputs that were on the ORTION_THRESHOLD limit (e.g. "(+++++)") because we would stop searching nodes of >= PORTION_THRESHOLD for neighbours, but still see if they were success nodes.