Actually, I think a Knossos project would take priority in the post Capella scenario.
Remember folks, Sol was *the* industrial center of the GTA, and odds are the GTVA still is in contact with the forces there (sure, radio takes its time, but iti s only a couple of years from Alpha Centaury)
But even if not, think of the shipyards, of the factories, refineries.... well, if they didn't nuke themselves or something as idiotic as that. (yeah, no guarantees here)
on any case, the time it took to build Colossus? I bet a large part was infrastructure to do so. and the first one always takes longer.
Now, I am guessing it would get some redesign, so it would get a better beam convergence, or maybe improved armor.... seems she was designed before collapsed core molby was incorporated, so she might het an armor and hull overhaul.
finally, what about a missile based system for Meson delivery? the thing is big, but why not tie it to a huge drone like missile? would make an interesting standoff weapon (specially if they can do a missile spam... now, picture it, meson missile spam! that'd be the sight)