Hello,

You have asked the most important question(s) and in doing so, you have created your best resolve. You asked, “My question is whether I should build a new website on the .com domain that I currently have redirected to the .co domain (and reverse the redirect). Is it worth it to give up the age, limited domain authority and organic traffic (albeit very low) of the .co site to have a faster, more user-friendly .com site?”

If you create new content on your (.com) site, which may be done via migration, then redirect the (.co) to the (.com), the benefits far exceed any minor inconvenience(s) despite how you import the (.co) databases. There are no visible losses to users. Organic or (*paid traffic – unless ads are updated) will still land on (.co) and seamlessly be redirected to your (.com), etc. Further since the (.co) is only being redirected, neither its age, nor its limited authority would be affected should you ever decide to use the (.co) in future.

I hope my response has provided you some clarity.
😊