The long objects idea neglects basic physics - unless the part hanging off the side is very light, at certain point it is going to drop down and peel the other

The long objects idea neglects basic physics - unless the part hanging off the side is very light, at certain point it is going to drop down and peel the other side from the belt, ruining the print. So in practice such machine will be limited to printing objects with maybe 2x the length of the belt max before the belt deformation and objects peeling off become a problem. You really wouldn't want to do continuous production like this - the printing surface needs to be cleaned too, glue or whatever you are using for adhesion re-applied, otherwise the adhesion and finish will suck over time, causing problems. How are you going to do it on a moving belt while the machine is running? Sure, it can be solved but the Creality machine doesn't have any provisions for it. And if you are producing thousands of not quite identical objects, buy three or four printers instead - the production will be much faster and more reliable than this belt nonsense, especially today when a printer can be had for less than $300 ...