Max Dynamic Point Lights
The property, Max Dynamic Point Lights which can be found under the Mobile section of the Project Settings can help reduce the number of shaders that are generated for dynamic lights. This feature is particularly useful for mobile games that do not require dynamic lighting.
To completely disable this feature, set the Max Dynamic Point Lights from 4 to 0 and then re-start the UE4 Editor when prompted.
Depending on the size of your project and the number of Materials used, the size saving you can achieve can range from just a few MB to the multiple MB ranges.
Using the default Third Person template, for example, we can see what the size savings are when Max Dynamic Point Lights are enabled versus when Max Dynamic Point Lights are disabled completely.
Packaged Game Size