Relative to previous comments made here: Anyone tried the Earlens and have any advice? - #19 by jim_lewis, here’s what I found out by going back to Smart Fit 1.3 on an older computer.
In Smart Fit 1.3, one could pick the fitting algorithm under Target Rule but it wasn’t applied until one right-mouse-clicked on a program tab and applied the change either to just the current program or all programs (one ear or both ears). So by only applying an algorithm to one specific program, you could have programs active at the same time that ran under different fitting algorithms. The change survives saving the patient profile to disk, closing, and reopening Smart Fit. It’s not ephemeral (and the difference in sound between programs showed up in my ears when using the Smart 3D app). In Smart Fit 1.8, as soon as you pick the fitting algorithm under Target Rule and apply it, it’s applied to all programs immediately. So in March, 2019 with Smart Fit 1.3, one could do with ReSound Quattro’s as with OPNs and experiment at the same time with different fitting algorithms used on different copies of the same program to compare the sound differences between fitting algorithms at the same time in the same environment but no longer (unless using the DIY info, you latch onto a copy of Smart Fit 1.3). It looks like the exact fit, though, may have changed a bit between version 1.3 and 1.8 so whatever one concluded using v1.3 might not carry over into v1.8.
The patient profile page in v1.3 did show the User Experience level setting in a dropdown but not the fitting algorithm in use. I guess ReSound wanted to eliminate the possibility that one could carelessly have one program set to one fitting algorithm and other programs accidentally set to something else. So now all programs have to use the same fitting algorithm.
Edit_Update: I also found my original post from back in March, 2019 where I described copying Neville and Volusiano’s experimental OPN idea for my Quattro’s in the Edit_Update note at the end: https://forum.hearingtracker.com/t/gn-hearing-introduces-resound-linx-quattro/37562/235?u=jim_lewis (probably using Smart Fit v1.3)