Question on 14-15 vs 17+ CVTs

[Jim Rogers]

I'm probably going to buy a used Mirage in the next six months or so, and I'm at the beginning stages of my research.

Since I'm seeing lots of 2015's available, I'm trying to determine whether the differences between those and the 2017+ models should affect my decision.

Thanks to this forum, I've found most of the differences (cam, brakes, rear axle, styling, etc.), but one of the major changes that I'm having more trouble finding information about is the CVT transmission change.

I currently have three questions:

--Did the Mirage ever change to the JF020EW/R? I have confirmed that the 2017 still had the JF015E, but don't seem to be able to find definitive information that it continues to use it beyond 2017.

--If the 2017+ still have the JF015E, how is the change in shift modes (D/Ds/L vs D/B) implemented?
*Fummins notes that he has put a 2017 cvt into a 2015-- were any modifications needed to the shift linkage to deal with the appearance of the Ds mode after the swap? Does his 2015 now have three modes after the swap?

--More generally speaking, how are the different shift modes implemented? If I had to guess, I would say:
*The difference between D/B (14-15) and D/L (17+) is that D uses both the first and second gears of the auxiliary two-speed transmission while B and L are restricted to only using the first (low) gear.

*Ds uses both the first and second gears of the auxiliary transmission, but the computer directs the pully/belt system to use higher rev ratios regardless of what gear the auxiliary transmission is in.

Is my speculation correct, or am I off base?

Thanks!