Keep in mind that, in the ATF’s eyes, anyone that isn’t the owner of the GG2 would be illegally making the gun… and the owner would be illegally engaging in the business of manufacturing a gun. (it is complete BS, and will hopefully be eventually overturned by a competent court, but until then…)
Their are a few ways that I can think of to let multiple people “legally” use the GG2. One way is for one person to purchase it, use it to make their gun, then sell it to the next person. Another possibility is to create a trust, have the trust purchase the GG2, then the trust could lease it to individuals for specific lengths of time.
I’m not a lawyer, and I haven’t stayed in a Holiday Inn Express recently, so please check with a 2nd Amendment savvy lawyer before doing any of the above.