I have a 10 speed shimano cassette. Under the “Elaboration on step 2”
9&10 speed
Then describes which spacers to use based on pocket or no pockets.
no pocket use EDCO spacer 2mm
with pocket Shimano original spacer 1mm and EDCO spacer 2mm.
my cassette has a thin (assuming 1mm) spacer can I then expect I am to use both?
Yes for the Shimano 10 speed cassette. They use the 1mm shim for installation on 10 speed freehubs. Then you add the 2mm spacer for installing a 10 speed cassette on a 11 speed freehub.