I'm coming along on my second acoustic data logger, and I'm interested in making contact with folks with peculiar or odd or unconventional requirements! to possibly work with, and to possibly have as beta testers.
The main features of this recorder are mission flexibility and low cost. The catch (there's always one!) is there's some hands-on user DIY involved (some through-hole soldering and mechanical assembly).
The kinds of missions I'm currently contemplating are plain ol' scheduled recording, in mono or stereo, and with or without GPS time stamps. This latter is to enable offline localisation (get the GPS coords) of sound sources when multiple units are used. The stereo facility may also aid in localisation (it's really about getting the direction to the sound source) and so can help with isolating sound sources (reduce the cocktail party effect).
Future missions depend partly on user feedback! At the moment I want to add LoRa networking but I'm eager to hear y'all's desiderata.