[lern_too_spel]

Use JSR305 with Findbugs or SpotBugs to solve the problem at compile time. Using Optional in Java does have a problem with extra object overhead, so if you want to avoid that, you should use another language like Kotlin or Scala.

[Nullabillity]

Scala's Somes cost an object as well, though (I believe) None is free in both Java and Scala.

[lern_too_spel]

You're right. Some is not an AnyVal.