Unestricted Sol. - 52.219-4 Usage

In an Unrestricted solicitation, do you automatically insert FAR 52.219-4 or Alt I? Our market research has indicated that there is not a reasonable likelihood of receiving offers from 2 or more responsible small business concerns, including HUBZones. In fact, we determined that we are not likely to receive any offers from HUBZones.

The prescription for use of 52.219-4 says that "before issuing a solicitation for general construction or construction by special trade contractors, the contracting officer shall determine if at least two HUBZone small business concerns can spend at least 50 percent of the cost of contract performance to be incurred for personnel on their own employees or subcontract employees of other HUBZone small business concerns." The prescription for Alt 1 says "The contracting officer shall use the clause with its Alternate I to waive the 50 percent requirement if the conditions at 19.1308( apply", which refers back to the contracting officer determination of at least 2 HUBZones spending at least 50% of cost...

I guess my question is, if a Contracting Offcer makes a determination that there are at least 2 HUBZones that can do either of these, why would the solicitation not be a HUBZone set-aside vs. Unrestricted? And if you have decided to go Unrestricted and have already determined that there is not the likelihood of receiving offers from HUBZones, do you automatically default to using 52.219-4 Alt I?

Not sure if I explained the confusion clearly, but my wheels have just been turning and turning on this one. Any insight is greatly appreciated!