Brucek,
Thanks. Will do that.
As it turns out, continued research this p.m. revealed that RPlusD (the newer incarnation of ETF5) no longer appears to differentiate between the way it produces Full Range and Low Frequency data (it generates a hybrid "Low Frequency Sweep + Mid/High MLS" signal for both), and both can be exported as wav files.
So all is right with the universe (at least for now).
Cheers,
--Wayne