"rather ingenious" is correct and usable in written English.
You can use it when you want to describe something that is clever or original in an understated way. For example: "His solution to the problem was rather ingenious."
"It's the present day and is all rather ingenious," McGann says.
It's rather ingenious and while pricey, a committed nail painter should invest.
While the ubiquitous vegan cheese was a little disconcerting, the food as a whole was intriguing and really rather ingenious.
When scrutinized, the economics of it are rather ingenious, and, paradoxically, somewhat compliant with the current edict to eat less meat.
"It's a rather ingenious practice," Chipchase says, "an example of grass-roots innovation, in which people create new uses for technology based on need".
We called it the European Coal and Steel Community, a rather ingenious construction presented by a French politician of German descent.
Similarly, the passing of Michael Jackson brought teary dollar signs to the eyes of Sony Pictures, who realised that the filming of rehearsals for the ill-fated This Is It shows could be reassembled as a rather less ingenious "tribute".
Ingenious rather than truly alarming.
There's a deal of heartbreak and anguish along with the hope and then a rather unexpected and ingenious post-modern ending so the reader, in effect, chooses the outcome.
Indeed, the most valuable workers are often not the most strenuous but rather the most ingenious and resourceful, and as their tasks increase in complexity and responsibility, the need for intelligence and imagination increases.
The caped crusader has become a thoughtless killer whose Batmobile is fitted with machine guns, rather than an ingenious detective who would save the life of his greatest enemy without a single thought.
