Adding an additional pre-amp would be fantastic. I am not in electronics, but I guess that the difficulty could be to get it working with low self-noise and low power consumption. SPM0687LR5H has a noise-floor of 24db instead of 31db for SPM0408LE5H-TB-6 and less distortion (Invensense’s latest ICS-40730 is given for a noise floor of 20db). A well designed additional pre-amp could significantly reduce the noise for more distant recordings.