4Dv16R2 and up uses a new web rendering engine called blink to replace the integrated web kit. This engine is included in the 64 bit versions. While the engine comes with alot of improvements over the old integrated web kit it does come with a size increase which is expected.

Below is an image containing zipped folders of 32 and 64 bit versions of the 4D folder for v16.0, v16R2, and v16R3. Notice the increase in size for v16R2 and v16R3 64 bit versions.