Wordpress Shortcode Block Tranform to Block Style and or Block Variation

Question

I am wondering if it is possible to do a block transform that uses a createBlock function that can set a className on a block. I also wonder if a block transform that uses a createBlock function can target a block variation.

I am working on a WordPress shortcode block transform and have slowly figured out how to make it work (see https://developer.wordpress.org/block-editor/reference-guides/block-api/block-transforms/#shortcode ). The code so far will allow you to copy and paste into the WordPress editor (I think you have to use right click and paste match styles {let me know if that is also wrong}) and will create a group with 2 paragraphs inside it. The last thing I am trying to figure out is if I can apply a box shadow block style (that is already registered) to the group during the transform. Currently I am trying to do that with className and have tried style, styles, etc...) I have tried to look through source code and many documentation pages, but I am not finding if that is possible. I was trying to just do it with className and it doesn't appear to work.

const transforms = {
from: [
{
      type: 'shortcode',
      tag: ["shadow"],
      priority: 1,
      transform: ( attrs, shortcodeObj ) => {
        return createBlock( 'core/group', { className: "is-style-box-shadow" }, [
          createBlock( 'core/paragraph', { content: attrs.named.heading }),
          createBlock( 'core/paragraph', { content: shortcodeObj.shortcode.content })
        ] );
      }
    }    
  ],
};

And this is the shortcode to paste into the editor

[shadow heading="Heading Test"]
This content should be accessible in the transform
[/shadow]

Alternatively, another solution would be to transform to a block variation that already has the block style defined, but I am not finding if that is possible either. Any advice would be really helpful to trying to perfect copy and paste into WordPress.