My last design with the Boron used a 10k pull-up (to Vbat on EN and 3V3 on RST) along with a 10uF filter to GND on each pin. I was more concerned at the time with reliability than power consumption.
I unfortunately stopped work on the Boron platform, primarily due to this other issue and the long time it took to get a resolution through Particle. Particle did eventually replace all my affected devices but not in time to salvage the project.