Is there any reason you wouldn’t consider using the Logitech renderers e.g. the duet? They are often found at bargain prices on eBay and have digital outputs ready for a decent DAC.

The more a machine “does” at the same time, the more mess it creates, the more perturbation there will be in signals timing etc.
This being true, the right question is of course “will this be perceivable”? And the answer depends on the level of quality you expect and on the level of the rest of your audio gear. If for example the RPI4 is connected to a quite entry level USB DAC, and/or with no particular attention to dejittering that connection etc etc, then I can assure you that having your RPI do 1 or 2 things at the same time will never make any difference. On much more sophisticated setups it will be the other way around.