That is correct: no time discount. That is because time is a separate modifier. Instead of speeding things up, the extra teams are doing a more throrough job and double-checking everything. You can, however, do a rush job and use the bonuses provided by having extra teams to cancel out the rush job penalties, which then lets you get the speed increase you're looking for.
Will have to look this over some more.
Thanks for the clarification. In regards to the first question, i meant "Do you only make one maintenance check for each unit, regardless of how much time passes between each scenario?".
For example, let's say you play one scenario and one game year passes before the next scenario occurs. Do you still only make one maintenance check? Do you need to make maintenance check for salvaged units and parts (e.g. a PPC you salvaged from a panther, an atlas with it's head destroyed, etc).
For repairing damage parts : I forgot to mention, if you are allowed to repair damaged parts that are not currently mounted on a unit, do location modifiers on page 171 also apply? E.G. A damaged PPC you just salvaged which is currently sitting in your dropship's transport bay.
Edit : Can you use extra time modifiers for maintenance checks or repair/replacement checks only?