That's the beauty of the modularity concept. You have a basic unit for crew, and everything else plugs into it.

I like the idea of an RV-sized caplet myself, but its shape is beside the point.

Once it's in orbit you plug in a propulsion unit (pre-fueled).
Return to Earth? Plug in a heatshield and a parachute.
Carrying some extra cargo on the trip? Plug in some luggage racks.
Landing on the Moon? Plug in some landing legs alongside the rocket motors.
Working on the Moon? Drop it in a wheeled cradle.
Going to Mars? Link a bunch together.

Done right, the CEV could prove to be a very versatile vehicle. Yours is one methodology, but there are a number of other good reasons for going to the Moon. Cislunar space is rich with opportunity, most of it involving billions of dollars of existing commercial assets between here and our Moon and the strategic consideration of access to resources, material and information as well as energy.

I fear though that we will end up with a compromise vehicle that will serve no end well. It'll get to the space station and back but have limited utility trans-LEO, requiring still another blank sheet vehicle for the taxpayers to choke on.

I'm trying to picture a future about 25 years out when private citizens can buy second-hand CEVs. That's when the real fun will start.