Interesting post, I have been using DNG lossless files for over 10 years and using DNG lossy files a lot in the last year so here is my 2 cents.
I started using the lossy DNG format as lossless DNG files (from Fuji raw files) were just so big (30-35mb) it slowed down my workflow and was taking up too much space. At first i only made lossy DNG for my B-roll pics, but then after a while I went all in with lossy.
I have ran a number of tests between the lossy and and lossless DNG and can say that 90% of time time you cant tell the difference, even in high ISO lossy looks the same as lossless. The only photos i have noticed a issue with lossy is high contrast scenes with a wide scale of bright and dark (e.g. clouds in below pic), In these scenes i noticed a small increase in noise in the dark areas at 200% zoom, so nothing major really.
If you want something in the middle between huge raw and fragile jpeg, lossy is a pretty good middle ground.