Nice. Some report 1.75 as the magic no trim number. Do your rims have divots in the back? I think that may make the difference.
That's exactly what I was about to say. I know from experience - the day before driving to Marco Island, Florida from NY, I lost a wheel while doing 65mph on a 4-lane highway. Thankfully I had noticed some weird handling and was slowing down to pull over to check, was doing about 40 when the ass end dropped to the asphalt, and the tire went bouncing past me, stopping over 150 feet down the slope and into the woods. That wouldn't have been bad, except we'd gotten about 12" of snow the previous day (on top of the 20+ already on the ground). I had to trek through waist-deep snow to get it, and then drag it up the 30* slope.
The 20" wheels I'd bought the 1 1/2" spacers for (on my old Tahoe) had a 1/4" deep recess for the hub studs to protrude into - the 16's in my signature did not. Even though they were hubcentric with a 1/4" lip, the 1 5/8" studs stuck out 1/8", preventing the flat surface of the wheel from touching the flat surface of the hub.
For my current Sierra 20's I have, I marked the stud locations on the back side of the wheels, and drilled some recesses with a 5/8" drill bit, problem solved.