POE Size Increase from 11GB (3.07.0.1318) to 15.9GB (3.7.1.1411) - why?

[AstralWanderer]

Checking the offline downloads in GOG for Pillars of Eternity showed a considerable size increase for the latest version.

For version 3.07.0.1318 the total download (base game plus both episodes of White March) came to 11.0GB.

For version 3.7.1.1411, the download has now gone up to 15.9GB - almost a 50% increase.

The patch notes between these two versions mention only two material changes - an update to the Unity engine (version 2019.4.11) and the addition of DirectX11 graphics. Aside from fixes, there appears to be no substantial additions to game content (areas, quests, dialogue, etc).

So why has there been such a large increase in file size? This is particularly ironic given that patch 3.7.1.1411 removed unused duplicate assets "that artificially increased installation size" - might they have been put back in again?