Resolve platform dependency from custom plugin

To compile proto files i use protobuf-gradle-plugin:

plugins {
  id 'com.google.protobuf'
}
...
protobuf {
  protoc {
    artifact = 'com.google.protobuf:protoc:3.12.3'
  }
  plugins {
    grpc {
      artifact = 'io.grpc:protoc-gen-grpc-java:1.30.2'
    }
  }
  generateProtoTasks {
    all()*.plugins {
      grpc {}
    }
  }
}

I want to hide this setting in a custom plugin and get protoc and protoc-gen-grpc-java coordinates from bom:

// bom/build.gradle
plugins {
  id 'java-platform'
}
dependencies {
  constraints {
    api 'io.grpc:protoc-gen-grpc-java:1.30.2'
    api 'com.google.protobuf:protoc:3.12.3'
  }
}
// app/build.gradle
plugins {
  id 'com.google.protobuf'
  id 'my-custom-plugin'
}
...
dependencies {
  compileOnly platform('org.custom.bom:0.1.0-SNAPSHOT')
}

Can I somehow get the resolved coordinates (com.google.protobuf:protoc:3.12.3 and io.grpc:protoc-gen-grpc-java:1.30.2) with the gradle API?

plugins.withType(ProtobufPlugin.class, protobufPlugin -> {
  project.getConfigurations() ...
  project.getDependencies() ...
  ProtobufConvention protobufConvention = 
    project.getConvention().getPlugin(ProtobufConvention.class);
  ProtobufConfigurator protobuf = protobufConvention.getProtobuf();
  protobuf.protoc(ClosureInterop.of((ExecutableLocator locator) -> 
    locator.setArtifact('...')));
});