I recall when I got my first album many years ago, applying the sheet of flags was fun.
Indeed. The only potential problem I see is finding a source for current (as of 2021) flag stickers. Does anyone know of a source that has all of the "legal" countries, as of 2021? That's what the simplified ASFEC album has...
I don't know if the sticker idea would work well with the comprehensive version, though. It includes forerunners, territories and other entities.
I guess someone could grab the free version (comprehensive) at the AlbumEasy/StampSmarter sites and change the graphics to color, and then self-print in color. That would be quite expensive, even if the album was scaled down to a simplified version. Not to mention the time involved to edit the source file, gather graphics, and etc. Definitely a project for someone with a lot of time on their hands...
Another factor is the maps. You can get tons of maps for personal projects. However, anything that is offered to the public must be public domain. I used CIA maps, because they are public domain and somewhat uniform in appearance.