Is there a Nomination Timer for Auction Drafts?

You can turn on the Nomination Clock towards the bottom of the SETTINGS area. The timer can be set for 35, 45, or 55 seconds. Once the time has expired for a nominating team, the platform will automatically skip to the next team, and it will not return to them until the next round.

How Can I Change Who Is Nominating?

It's useful to know that the commissioner has the capability to pause the nomination clock, as well as "Change Team Nominating" at any time during the draft, should they need to revert any nomination skips via the in-draft "Change Team Nominating" tool (accessible via the (...) commish tools drop-down button:

Doing this will skip the current team nominating to whomever you select, and then return to that nominator at the next player nomination point.