Below is a starting point for a /boot/config.txt matching a Raspberry Pi 3 B+. Most importantly is enabling turbo mode to prevent the cpu from changing its frequency dynamically. This will have a negative effect on Twitse time measurements.
Next the RPI’s are overclocked. They are not exactly speed kings and they can use a little boost. Common sense would dictate that overclocking must have a positive effect on the Twitse time measurements but this haven’t really been verified.
# See /boot/overlays/README for all available options gpu_mem=16 dtparam=i2c1=on # client only dtparam=i2c_arm=on # client only dtparam=spi=on # client only dtoverlay=hifiberry-dac # client only force_turbo=1 arm_freq=1200 core_freq=500 sdram_freq=500 over_voltage=2 over_voltage_sdram=2 initramfs initramfs-linux.img followkernel
(This is from an Arch installation)