So since I started this ? about Costco Jabra and whether the fitting software allows for Frequency Lowering here is what I believe to be the status (as well as other info which I already knew from other threads here, reading white papers from the various mfg, and/or articles on audiologyonline). The Costco Jabra most likely has frequency lowering however per @MDB post below Costco locks Resound and therefore presumably Jabra and therefore it seems likely that only someone with access to Costco software for Jabra fitting could go DIY. {Above was edited to incorporate info from post below from @MDB and @Raudrive.
All of the major HA Mfg offer their own version of frequency lowering; for some e.g. Phonak their strategy is in the 2nd version of that strategy. While the full blown HA of all of these MFGs offer frequency lowering in the fitting app AND for some MFGs the Costco HA option from that MFG also offers frequency lowering (although sometimes named something different, but still working in the identical manner) for some MFGs e.g GNHearing with Resound versus Jabra that the Costco HA “cousin” HA is dumbed down and does NOT offer frequency lowering.
If indeed this turns out to be accurate, then at least for some forum members for whom frequency lowering might be a good adjunct to the standard fitting approach then this becomes a major and perhaps deal breaker difference in considering KS10 versus Jabra Pro both via Costco.
From what I have read, frequency lowering is much more of an art form for a fitter than standard fitting approaches based on amplification; the criteria of who might benefit from frequency lowering does not have definitive guidelines, but does seem to have some guidelines of who would NOT benefit; that the limited research is quite inconclusive some research showing some benefit, other reserarch not showing benefit thus lots of individual differences; anecdotal comments from some members here indicate that some have received great benefit; that any frequency lowering strategy always introduces some “distortion” into the HA output and therefore the approach is not a free lunch and has trade off AND also and this is based on two research papers that the less aggressive settings regardless of the freq lowering strategy always introduce less distortion than the more aggressive settings and so the fitting recommendation is use the lowest freq lowering settings that provide some improvement.
In my own reading on the subject I found this long professional article to be a very good explanation and overview of frequency lowering ( 20Q: Frequency Lowering Ten Years Later - New Technology Innovations Joshua M. Alexander 20Q with Gus Mueller Hearing Aids - Adults Hearing Aids - Children VA Selections 18040 https://www.audiologyonline.com/articles/20q-frequency-lowering-ten-years-18040)). I will save any additional ?s I have about freq lowering for a different thread focused only on that topic as current thread is an HA comparison thread.
