Activity codes should be used to protect customisations in X3 and not be used for sizing. I suggest that Sage introduce a new sizing field for screen fields this would mean that we can still use a custom activity code for protecting changes that we make to customer screen fields. Currently if a field uses an activity code for sizing it means that either you have to protect the whole screen block or even whole screen using an activity code or create your own sizing activity code. This has been an issue ever since V130 and needs addressing.