With IntelliJ 2016.1.4, which I am using, things has become easier.
File -> (Other Settings-> Default Settings) |Settings -> Editor -> Code Style -> Scala
Select tab Other
- select option
Replace => with unicode symbol
- select option
Replace -> with unicode symbol
However if one wants to support other unicode characters as in scalaz, then
maybe, Live Template might still be the way to go. I haven't verified it.
With IntelliJ 2019.x.x, I recommend using Font Ligature along with Jetbrains Font like Jetbrains Mono especially when the use of unicode arrows are getting deprecated in Scala 2.13+. Besides, I found that the unicode symbol don't gel with Scala Repl.