To have much chance of domestic USA upgrades, you need high status on the USA carrier you fly. Status on alliance partners doesn't help much, if at all, for this. You could decide to drop down from 1K to Plat or even Gold, but then your upgrade rates would go down by a lot. OTOH, *Gold with an airline other than UA will allow you to use UA lounges for even domestic flights as well as *A lounges when flying international *A itineraries.