Just got some more info.
Apparently the copper terminal is plated or is made of 'aluminized copper', so attachment to an aluminum spacer should not be an issue.
Also, a makerspace member recommended "
noalox". It claims to:
•Anti-oxidant
•Reduces galling and seizing on aluminum conduit joints
•Suspended zinc particles penetrate and cut aluminum oxide
•Carrier material excludes air to prevent further oxidation
•Improves service life of aluminum electrical applications
•Costs a lot!
Ok, last one I added.
But, with that new info and some noalox I think I should be in pretty good shape.