Thanx for a thorough post on leather care
You like me has the black nappa with white contrast stitching. What worries me when applying leather care products is that the white thread might turn yellowish or even brown after some treatments.
I don't know the products you mention, so this is more like a general worry. Do you see any sign of miscoloring so far (looks perfect on the pics though)?
Luckily the climate here in Norway is very gentle to leather interiors (meaning chill climate and not too much sun). I have another car as a dd, so a treatment twice a year should do