Hi Danilo,
Thanks for the report.
Unfortunately we were not able to reproduce the problem.
We have approximately the same frame rate whether the node is an "Apply curve" node or another node.
However we noticed some lags when the terrain is big (such as 32000 x 32000) and the user keeps on moving the mouse cursor on the 3D viewport at a fast pace to pan or rotate the camera.
We've just fixed this issue. The fix will be in version 1.10.1 to be released in a few days (not in version 1.10.0 which has just been released today).
Hopefully it will fix your problem.