When the design alternative consists simply of material assignments, an easy answer is attribute manager (AM).
Create a new material called 'conference room carpet' (e.g.) that is a copy of blue carpet for your example. Put a space in front of the material name so that it sorts to the top of the list. Repeat for other elements.
In AM, select those materials (or all materials), overwrite (NOT append) to the right and save in a file called 'Design One' or whatever. Change the materials to your second design choice. Repeat. Now, just use AM to load the materials for each design choice.
When the design is
physically
different, then I would go to the approach of using layers, hotlinked modules, or markup tools. When it is only different in surface or edge appearance, I would use attribute manager.
Cheers,
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB