correct, you have to mail the token to the ALT and open it up there..i got everything from VR to uncommon on all my characters last go around..last go i never got UR or EPIC...(spent about 3mil dil)
i just spent 400,000 dil on boxes - no UR or EPIC again :(
but the upgrade tokens are 2nd only to the omegas...and help gild so much stuff, in fact i just used my last phoenix upgrade from last year about 2 weeks before this event started (last upgrade weekend), so they do last a while.