No they are not.
The first 1mm spacers I bought seemed fairly poor made so I went back and bought a box made of some higher grade of steel (A2). The new looks more uniform but when I measured them most are approx 0,96mm but they vary between 0,9 and 1,0mm. They are also not 100% flat which also affects the measurements and as we are talking about very small differences I must admit that I just picked some random washers from the box when I mounted my disc.
Also ended up using some ISO 7380-2 M4x14 (A2) torx screws. I think the stock screws (M4x12) would still be sufficient length but the new also have a head height of only 2.1mm vs stock screws with ~3.0mm so there is a bit more clearance to the frame.
