One can receive updates to binary packages for the current -stable release from M:Tier[0] . They also host binpatches for security vulnerabilities in base which can either be installed manually via pkg_add or automatically with their openup[1] tool.
I like the idea, but doing so still adds a great deal of complexity to a supposedly simple design and adds a large amount to the size of the printer if one accounts for the use of legal paper.
While I wouldn't mind settling on a standard paper size, the design still leaves a great deal to be desired. It appears to be more of a gimmick than anything.
It seems as though a more practical (though perhaps more dust-prone, when empty) design would do this partially upside-down. Rather than allowing the printer to move downward though the paper, why not load the paper from the top?
One could set a full stack atop something similar to his current design using the rollers, and the finished pages could exit through the front in order to prevent them from building up below. The final roller could simply be removed and a slit added to the front such that the finished paper could exit the printer cleanly. A solid plastic sheet could then be added to catch the printed paper which folds back atop the body of the printer when it is being transported or simply not in use, perhaps to prevent the aforementioned build-up of dust.
This accomplishes Yamamoto's goal of removing the paper tray and simplifying as well as shrinking the design while avoiding the dangerous consequences of brushing past the printer while it is atop a high stack of paper.
Of course, none of this addresses a central flaw with his design. Even if two models are produced for Letter and A4 paper, there are still many other sizes in use, and there appears to be no easy way to adjust the sizes of the intake and output areas without the dreaded paper tray.
0: https://stable.mtier.org/
1: http://www.mtier.org/index.php/solutions/apps/openup/