"Yet they serve different purposes and the aim of the workshop to show and not selling!" :) really? then you are ignoring all the hundreds of thousands of people voting in workshop? you think their vote doesn't matter? Showing something is selling. In the store yes most items are equal like you say, they all have the same…
If one wants to pack UV shells from the same object across multiple UDIM tiles, then one has to apply multiple materials to that one object and assign the corresponding faces to the materials. This is thankfully quite easy in Blender: * Select all objects and enter edit mode (make sure UV sync selection is on) * Roughly…