A much-needed fix that allows for simple creation of Door_Elevator Moving Platforms directly within Constructor, Platform Assist will save both time and frustration when creating interiors.
This tool automatically overrides the entity switcher, so creating a platform will invoke it automatically. You should notice that, when selecting "Door_Elevator" as the entity type, all the brushes will have the same entity id.
Additionally, it can be used to combine multiple brushes into a single entity by selecting the brushes and then using the tool manually. A window will appear with a list of entities that you can select. Picking one will make all the selected brushes use that entity.