Board Game Arena

The Automatically Passing on Bids is a great feature and everyone should consider using. Especially in turn-based games as sometimes one player exhausting the exploration track can take several hours. Setting up automatically passing bidding on 1s or 2s greatly speeds up the game and can help to ensure your timer doesn't end up in the red.
I usually have 1s and 2s toggled to automatically pass. You can pick which races and values to auto pass bidding on. It really speeds up exploration for my opponent. Automatically passing on bidding can always be turned on/off or updated during the game if a situation arises where I desperately want any value from a certain race. So turning it on is not permanent.
The table is at the bottom of the game area on the main screen.

I am looking under options and do not see it

It's at the bottom underneath your opponents lords and above the How to play section. It really helps speed things up in turn based games, especially with 3 or 4 players. You can always turn it back off if you feel you might buy a 1 or 2 in order to get a certain lord on your next turn.

It is very useful, and I wonder if it might make sense to change the UI to make it more visible...because it's down at the bottom of the screen, below the main board, I think that some people may not ever notice it.

It does speed things along, especially when there's some crappy 1 Crab card for sale for that's going to cost 2 Pearls and nobody is going to buy it anyway.

I am not sure where it would be better placed. I would hope anytime someone first plays a game they look at the entire game area down to there the how to play, tips, options and music are.