The second would would likely see total completion, and would likely be slightly different, with better materials or construction all around, learning from the mistakes of the first model.
The GTVA did learn from their mistakes. That's why they didn't build another Colossus and instead went for a high mobility force, purpose build for quick manouvering and shock-jumping.
And I have to agree with Luis Dias here. On one side we have a magically conjured up Colossus, clearly defying BP canon, but on the other hand we may not bring more Durgas into the scenario than the UEF has, because it would defy BP canon? Doesn't make much sense.
Also a Colossus isn't just going to magically appear out of thin air (or vacuum). It has to be build using money, materials and manpower (not to mention it takes time). Ressources that in BP canon went into the construction of the rest of the fleet and the portal.
So if the GTVA had a Colossus, there wouldn't be any Titans and Raynors and far fewer next-gen Corvettes, which would make a massive strike at the colly much less risky for the UEF, because the GTVA simply dosen't have the necessary ships to mount a "backdoor offense", or at least not an offense devastating enough to equal the loss of the Colossus.