You absolutely don’t want a built in dac ,a Quality dedicated dac is so much better.
withut question , why do you want to change your current electronics ?what is your budget for a dedicated dac ? Please remember your Ethernet cables ,as well as usb cables make a huge difference , in your case I would recommend the Denafrips Pontus2 12 th anniversary dac ,with the Iris DDC upsampler which clears the signal then has a better master clock for $2500 a no brainer ,
it has a I2S input which is the best Wireworld HDMI has the exact pin out for the I2S cable -HDMI , the Mac dac not even close in musicality . I have heard most everything from McIntosh , this applies to all ,a good external dac is much better
for you just have much area for isolation ,power supplies and better parts quality .