With my Lampizator DAC and their USB module it’s a no-brainer - USB!
Their module uses a 32-bit engine capable of 384 kHz speed. It is asynchronous and uses two internal clocks for re-clocking. It also is self powered from an internal power supply so you use a non-powered USB cable. No power is taken from the computer and the noisy computer line is physically interrupted and insulated.
Also it’s not converting to SPDIF - it is much better than that - it converts to i2s and it is connected DIRECTLY to the DAC chip, bypassing all input and receiver stages. This really is the best USB solution - at least right now.
If you can’t go USB, then go coax. But don’t go optical - it may not be able to handle data flows over 96.