But there was a time, as they were fiddling with this feature where you could customise it to do something like what you are describing or the tab search. And I think you could also fiddle around with the background config settings.

I'm not happy with the current instant search implementation, as it does both page content and tab titles and I pretty much 100% want just tab titles. It made the operation very fast for me, as it would only pop up a few hits and I could select the right one very quickly. Now I have to type more and/or pause to select what I want.

Similar here was the old vertical Ctrl+Tab behaviour with full page preview. easy to select the right one. In fact this was one of the final features that got me to switch from Firefox's brain-dead horizontal cycler. Then Opera did the same! 😞

Anyway, it's generally really annoying when they remove features you were used to and replace them with inferior substitutes. But, it's subjective, which is why we need customisation.

However, all the software vendors are guilty of this!

For example for searching in google user can define a searchprefix for example "g". When typing "g how is the weather in vienna" will search in google. Same with "b how is the weather in vienna" will search in bing (of course when "b" was defined before as search prefix vor bing).
Firefox has that feature where you can define search keywords for any website by calling the website, focusing on the search input textfield, clicking right mouse and set a keyword for the website.
Would be fine if this will be implemented on Opera for Android.

Regards