Yes, more or less. But there are some protections in the marketplace to prevent people from having an edge/advantage, so for example the latest "on open" bids are accepted only until 2 minutes before the market opens. So you cannot wait until last second. And if you could wait until the last second, everyone else submits their bids several minutes before the market opens, so you still cannot know what bids is everyone submitting. And the exchanges determine the price by comparing all submitted bids to submitted offers (to sell) and available quantities between buyers and sellers. So really the opening price is quite random, although similar to pre-market price.
And I think that all quants / algo programmers go through the process of trynig to make profit based on the opening price, but this is always a mistake. If such method existed then one company would make tons of money while everyone else would lose and stop trading at market open. So the whole process must be balanced and fair to everyone.
But if you can forecast minimum/maxium opening price that you want to pay then you can use limit-on-open orders and try to "catch" some stocks at a good price sometimes. This may just not work too often, so you would need to place thousands of orders every morning and hope that some of them will be executed at your price, and that the price didn't drop because of some news or other reasons that you don't know.
While I don't believe that this is related to IBKR model or any model, because the opening price is mostly determined by humans (or trading companies computers that use own rules) and doesn't always need to be related to previous price. Generally the opening prices cannot be known until after the market opens and this price is announced by the exchanges.