With a recent download I have two Epiphany EXE files with same name: "setup_blackwell_epiphany_3.0_(65957).exe". But different sizes: 629557 and 629963. The smaller of the two was downloaded 7/24/2023 and the larger 9/12/2023. These files surely are different builds and should have different names.

Anyone else see this? Or care?

This may have been due to GOG's update servers experiencing a severe malfunction (for several days) last July (?), at the same time that the Blackwell titles were being updated to their AGS 3.0 engine versions. I remember all Blackwell titles specifically being affected by this issue, and for quite a bit after the issue was resolved for other titles.

So the smaller one you have from July may be a product of GOG's malfunction and (I assume) it can be discarded.

I have the one with size "629963" and it can be installed without issues.

The only difference I see after extracting both are the game ads shown during installation.
All game relevant files are identical, hence no new build number I guess.

Thank you all.