As far as I understand, this feature was present, but for various reasons it was removed (https://invent.kde.org/plasma/plasma-workspace/-/commit/820c5b1a27c2b534f679e09de5b2b68378ad9f72). But that feature is really useful for non-english locale system (when `Name` is Cyrilic for example), or just sometimes you need to find it by the name of the executable. I think, we can consider the option of enabling the search by Exec through an optional checkbox in the plugin settings. Also I think Exec= field value should be cleared of env variables and launch parameters before use that `ExecutableName` in `void matchNameKeywordAndGenericName()` method, where the search query is checked for matching with one of the search criteria.
Sorry, I don't think we'll be bringing the feature back. It was just a can of worms that generally worsened search results in many ways. Wanting to search for the English name when using another language is valid, and tracked with Bug 467924. We're hoping to have that done for Plasma 6.