Never mind. I guess creating the columns with a custom name in the script does work. I think I was just referencing them wrong:

nSearch.createColumn({
    name: 'formulanumeric1',
    summary: 'MIN',
    formula: 'CASE WHEN {memberitem.inventorylocation} = {memberitem.preferredlocation} THEN NVL({memberitem.locationquantityavailable}, 0) END'
})