Cavalary: GOG gift codes have no region restrictions. In fact, they can even be redeemed by people who couldn't purchase the games in question themselves, because they're blocked in their region. So gift codes are treated as region-less purchases and priced accordingly if purchased from regions that benefit from discounts in case of buying the games normally.
And, perhaps more importantly from a business perspective, this prevents people from (or with VPNs from) regions that benefit from massive discounts from purchasing cheap codes and then trading or selling them for more.

Shmacky-McNuts: Providing original files makes more sense. Its something staff can provide right now. That is actual preservation and works great for cross platforming by default. Obviously the gog version will be the default, but having original files, minus DRM makes sense. Put the originals in the drop down menu, so noobs dont get that by accident.

Plus having the last best known to function Win10 version in the drop menu would be even better, for those unable to move to Win11.

idbeholdME: Exactly this. That would make GOG stand out. But again, I fear GOG can only offer what the publisher allows.

Also maintaining 2-3 previous installer versions in case an update does something not everybody might like so you can still back it up after the fact.