PPS driver, assigning gpio

Apparently the idea of a gps derived time server for ~$35 was my tipping point. I bought a GL-iNet GL-MT300N-V2 and a Beitian BN-180 gps module (*1). I think I've wired things up well. But I've stalled on getting the pps kernel module to work.

My question: Is there any way to configure pps-core or pps-gpio via kernel module option, config file, or anything else short of custom compiling OpenWRT? I can't tell if I'm missing something in the documentation or if it's really impossible to just tell the module which gpio to use somehow, some comments direct me to editing the dts files before compiling, other comment refer to dtoverlays but it's not clear that applies to OpenWRT or something else (mostly Rasp Pi discussions).

For reference or for other's who might be interested.
Hardware: GL-iNet GL-MT300N-V2 and Beitian BN-180 gps module
The BN-180 does NOT have a pps output pin so I don't really recommend it but it's common, available, and cheap. I happen to be able to solider an additional wire on to the correct end of the pps led resistor.
I flashed the device to OpenWrt 19.07.4, disabled dhcp, renamed the lan IP to something that wasn't the same as my home network, enable the wifi as a client so I could easy download software.
Installed stty, and kmod-pps-core, kmod-pps-gpio.
If I:
stty -F /dev/ttyS0 9600
cat </dev/ttyS0
I get regular GPS NEMA lines so good there.
If I:
echo 46 >/sys/class/gpio/export
while true; do cat /sys/class/gpio/gpio46/value ; done
it looks a lot like the pps signal is working
If I:
echo 46 >/sys/class/gpio/export
echo "rising" > /sys/class/gpio/gpio46/edge
cat /proc/interrupts
it looks to me like the gpio is triggering regular, once a second interrupts.

I think at this point if I can figure out how to get the kernel pps stuff working I could install ntpd and maybe gpsd and have a working stratum one.