Revert urlbar search engine behavior

[s41fg25derst46e]

I am currently on Nightly 161.0a1 (2026-11-01).

Before, I used to be able to to type e.g., "eb" to start an eBay search then add a space and type my query. However, due to recent changes in behavior, if I want to search for an item that shares the name of another keyword, it erases what I previously wrote and locks me into that new search engine. For example, if I want to search eBay for a "go board", I will instead end up in a Google search with "board" as my query since I use "go" as my Google keyword.

The previous behavior was perfectly explicit and user-friendly and I like to keep my keywords concise. The new behavior is a regression and there is apparently no way to change it back even after briefly surveying about:config urlbar options.