Exhaust Seal Washers

I believe that I've seen this issue discussed on the Forum before but can't find the discussion thread for the life of me. My bike is a 1974 850 MK 2 with stock exhaust. The new exhaust seal washers I received from Andover (part No. 06.3995) have a flat face on one side of the washer and a slightly rounded face on the other side. I didn't notice when disassembling the exhaust system which way the washers were oriented. It seems intuitive (always dangerous) that the flat side goes against the head and the rounded side is in contact with the exhaust pipe but I'm not even sure if it makes a difference, although the fact that the two faces of the washer are different kind of implies it might. I've checked all my reference material and can't find any info on this issue. Does the orientation of the seal washer make a difference? Thanks in advance.

Flat foundation side (load and sealing side to the softer alloy) to the port, crush side (convex when new) to the header flange.

That’s the way I was leaning. Thanks for confirming.