That definitely sounds about right based on my experience. I bought this one that claims to have an installation height of 0.75mm, but I think that’s a bit optimistic. My calipers aren’t as precise but the heatsink is about 0.4mm and the thermal pad looks to be about 0.5mm, there’s a little compression but I’d say it’s adding around 1mm to the height
On installation I noticed it does stick up slightly compared to its surroundings, about 0.6mm above the adjacent battery. When I first secured the keyboard housing it looked like it was bowing ever so slightly, but after I poked it it’s looked normal since, and if I use a level it’s flush across the surface.
I do suspect it’s applying a slight amount of pressure between the keyboard housing and the mainboard, if it fits it just barely fits. Debating whether to leave it installed.