hide.lua

    local frames = { DUF_PlayerFrame,                             -- table of frames you want to show/hide
                     UnitExists'target' and DUF_TargetFrame,
                     UnitExists'pet' and DUF_PetFrame,
                     UnitExists'targettarget' and DUF_TOTFrame, } -- etc.
                 
    local d = CreateFrame'Frame'
    d:RegisterEvent'PLAYER_ENTERING_WORLD'
    d:RegisterEvent'UNIT_HEALTH' d:RegisterEvent'UNIT_MANA'
    d:SetScript('OnEvent', function()
        if event =='PLAYER_ENTERING_WORLD' then
            for _, v in pairs (frames) do v:Hide() end
            d:UnregisterEvent'PLAYER_ENTERING_WORLD'
        end

        if arg1 ~= 'player' then return end

        local hv =   UnitHealth'player'    local pv = UnitMana'player'
        local hmax = UnitHealthMax'player' local pmax = UnitManaMax'player'

        if UnitAffectingCombat'player' or (hv ~= hmax or pv ~= pmax) then
            for _, v in pairs (frames) do v:Show() end
        elseif hv == hmax and pv == pmax then
            for _, v in pairs (frames) do v:Hide() end
        end
    end)

--