Upgrade queue gets new items at front *or* rear of queue

It'd be really helpful if it was possible to add new upgrade items to the rear of the Vehicle Building's instead of inserting upgrade requests at the front all of the time. For example, if I have a much-needed tree harvester next in line in the queue, I don't want upgrades to other vehicles to supersede that. So - if there was a button for queueing at the front (immediately after the current build is finished) and a separate button for adding an upgrade to the end (rear) of the queue, that'd really help.
At the same time, I'd also like to see a way to re-order the queue (drag&drop).

Should have said " rear of the Vehicle Building's queue" instead of missing the word queue. OOPS.