Nice to see crystal X1, however that is only 32.768kHz, no support for 8-48MHz clocks or TCXO ?
There is room on PCB back side for active CMOS oscillator footprint (2520/3225?) at least and an optional series capacitor would support clipped-sine crystal oscillators.
Also P1.6, P1.7 need isolation jumpers when X1 is fitted, the very long traces on P1.6,P1.7 will compromise the XTAL oscillator.