Jenkinsfile using parallel and when to pick one of multiple stages to be executed

SwitchDeclarativeJenkinsfile.groovy

#!/usr/bin/env groovy
// see https://jenkins.io/doc/book/pipeline/syntax/

pipeline {
    
    agent any
    
    parameters {
        booleanParam(name: "RELEASE", defaultValue: false)
        choice(name: "DEPLOY_TO", choices: ["", "INT", "PRE", "PROD"])
    }
    
    stages {

        stage("Build") {
            steps {
                sh "./gradlew build"
            }
        }
        
        stage("Publish") {
            parallel {
                stage('Pre-Release') {
                    when { expression { !params.RELEASE } }
                    steps {
                        sh "./gradlew preRelease"
                    }
                }
                stage("Release") {
                    when { expression { params.RELEASE } }
                    steps {
                        sh "./gradlew release"
                    }
                }
            }
        }

        stage("Deploy") {
            parallel {
                stage("INT") {
                    when { expression { params.DEPLOY_TO == "INT" } }
                    steps {
                        sh "./deploy int"
                    }
                }
                stage("PRE") {
                    when { expression { params.DEPLOY_TO == "PRE" } }
                    steps {
                        sh "./deploy.sh pre"
                    }
                }
                stage("PROD") {
                    when { expression { params.DEPLOY_TO == "PROD" } }
                    steps {
                        sh "./deploy.sh prod"
                    }
                }
            }
        }
    }
}