multiple LIRC ?

I'm trying to build a robot that does not
have an MCU or FPGA for the real-time
stuff.  So far so good: the periodic
timer triggers within +/- 4 microseconds
of when expected.

The next problem is to accurately time
a set of incoming pulse streams.  One
is for an IR receiver and it occurred
to me that LIRC mode2 is exactly right
for all the pulse streams.  Unfortunately
you can not load LIRC multiple times.  I
was able to create multiple instances of
the LIRC driver but could not open more
than one at a time due to an IRQ conflict.

Any suggestion on how to use interrupts
on GPIO pins to accurately measure pulse
widths?

The platform is a RPi3 with a 4.4.7 kernel.

thanks
Bob Smith