Forthcoming change to CPR 47.14:
“(8) If an assessment is carried out at more than one hearing, then for the purposes of rule 52.4 time for appealing shall not start to run until the conclusion of the final hearing, unless the court orders otherwise.”
It currently runs from the date of the judgment on the particular issue, which can make a decision as to whether to immediately appeal more difficult. It is only at the end of a detailed assessment one has a full picture. For example, a party may want to appeal a specific point if it will make the difference between winning or losing on an offer but otherwise would be prepared to let the decision stand. In fact, many costs judges already make such an order staying the time for appealing where the issue arises, but it does need someone to remember the problem.