If you’re doing
Option 1 (no mains anywhere on the PCB), then
J8 should represent
an off-board “load-side mains” connector (i.e., where the switched hot and neutral leave the relay module and go to the load), purely for
documentation / wiring reference.
And the key rule:
J8 should
not connect to any low-voltage nets (5 V / 3V3 / GND / ADC signals). It just anchors the net names
LOAD_L and
LOAD_N so it’s unambiguous how the external relay module and load wiring are intended to be hooked up.
If you want it even clearer, rename/annotate
J8 in its value/description to something like
“OFFBOARD_LOAD_OUT (wiring only)”.