It is definitely possible, there are just a lot of variables to consider when deciding if it is right for the application. The immediate problem is this would make it challenging/unrealistic to remove and repair either part individually. If this is not a problem, I would probably start looking at weaving/looping the carbon fiber around the mild steel structure. That way you have the structural strength of the carbon fiber holding them together, not just the adhesive. I don't know this for sure, but it may not be ideal to adhere something to the surface of the carbon fiber, because it may be more likely to just pull the lamination apart before completely structurally failing. If anyone has experience with this I would love to hear more.
I cannot lie. They do what they say. As far as being a customer for them service is fine. However, I would highly recommend reaching out directly to a contract manufacturer. Every time you use Xometery, you are taking money out of the hands of the shops actually doing the work. Xometery makes a profit off every sale, manufacturers break even. If you are looking for quick CNC machining, fabrication, 3d printing, or welding work completed feel free to direct message me.