I don't have a recent increase - but I didn't build anything on 292.26 - this is just comparing to what I have on my hard drive - there's a decrease in size overall from May 2020.
Nov 2019 - 15 579kb
May 2020 - 17 454kb (I think this is when I was testing 2.5+ for the first time)
Oct 2020 - 17 198kb DX 9
Oct 2020 - 23 786kb DX 11
Nov 2019 - 38 216kb
May 2020 - 51 546kb
Oct 2020 - 44 566kb (dx 9)
Oct 2020 - 50 727kb (dx 11)
Unless it's a particular extension.
OK, actually the bug was in the build 292.26, the "Optimize image size in RAM" option was not correctly handled in this build, due to an outdated file. This is this line in the build 292.27 change log:
- Editor: DirectX 11 mode, opaque images were incorrectly built, causing bigger loading times.
Apparently it was more than a problem with opaque images, unlike what I thought.
So the bigger size is due to the "Optimize image size in RAM" option and it's normal (it gives the same size with the build 292.22). With this option images are less compressed to favor faster decompression, faster loading time and smaller RAM use.
There is another problem with the build 292.27 (and 292.28), one of the changes done to try to avoid false positives caused the runtime not to be compatible with Windows XP anymore, I'll revert back this change and I'll release the build 292.29 tomorrow (other changes have been done to try to prevent false positives in this build).