I use gain change a lot. It is permanent, and once done, doesn't take any resources to accomplish.

The mixer moves use resources, and there is a lag that is equal to the buffer size of the audio stream. Obviously smaller when using ASIO than MME.
However, when you do the final merge down, there is absolutely no lag, so getting this set just right can be a little tricky if the section is a continuously playing part. If it is a part on its own, with a break before/after it is easier to do.
I like to hard write most changes like this.


Just another view on it.

I do not work here, but the benefits are still awesome
Make your sound your own!