[Wimpface]

Not sure where I found this but I've been using it for the last few months in various layouts and it seems to work fairly well.

Replace YourLayout with your layout name (who would've thought...)

local testui = TestUI or function() end
TestUI = function( msg )
    if( msg == "uf" or msg == "unitframes" ) then
        oUF_YourLayoutTarget:Show(); oUF_YourLayoutTarget.Hide = function() end; oUF_YourLayoutTarget.unit = "player"
    elseif( msg == "boss" or msg == "b" ) then
        oUF_YourLayoutBoss1:Show(); oUF_YourLayoutBoss1.Hide = function() end; oUF_YourLayoutBoss1.unit = "player"
        oUF_YourLayoutBoss2:Show(); oUF_YourLayoutBoss2.Hide = function() end; oUF_YourLayoutBoss2.unit = "player"
        oUF_YourLayoutBoss3:Show(); oUF_YourLayoutBoss3.Hide = function() end; oUF_YourLayoutBoss3.unit = "player"
    elseif( msg == "buffs" ) then
        UnitAura = function()
            return 139, "Rank 1", "Interface\\Icons\\Spell_Holy_Penance", 1, "Magic", 0, 0, "player"
        end
 
        if( oUF ) then
            for i, v in pairs( oUF.units ) do
                if( v.UNIT_AURA ) then
                    v:UNIT_AURA( "UNIT_AURA", v.unit )
                end
            end
        end
    end
end
SlashCmdList.TestUI = TestUI
SLASH_TestUI1 = "/testui"