"even smoother" is correct and usable in written English.
You can use it when describing how something has improved or become better than before. For example, "The new version of the app is designed to run even smoother than the last."
(You can make it even smoother and saucier by whisking in a little yoghurt).
BOSTON — They are two significant parts of the future for the Tampa Bay Rays, the smooth third baseman and the even smoother center fielder.
His follow-up was, arguably, even smoother: "I'm probably going to have a few drinks and then come on to you.
Because it's sampling 120 times per second, it's able to make the Pencil appear even smoother, with the tip following the draw point precisely.
To solve the problem, Covetly began offering pricing and curation services as a way to make the process of buying and selling even smoother on mobile devices.
Try facial masks to get your skin even smoother.
The reduced length, significantly cut-away from the aft, made it difficult to keep the ships on a consistent course, even in smoother waters.
That will be true, one imagines, even with the smoother official edit that the record company is to release soon.
The city at large also turned on the Tammany style, even Mr. De Sapio's somewhat smoother version, although history shows the reformers did not entirely vanquish the patronage and corruption.
It filled every minute depression in the imitation leather of the car seats; on the smoother surface, even after it had been scrubbed off, it left a clear trace, like the drag of a snail, glinting when the light fell on it at a certain angle.
Difference of intensities of adjacent pixels may not be an edge point; any such technique may embed data in smoother parts even though there are some unused prominent edges.
