Bootstrap 4 theme that utilizes the new D8 Layout Builder?

So I am converting one of my D7 sites to D8 and have decided to go all in on using the new layout builder. I think it's really awesome and will be great for our content editors. I'm wondering if anyone is aware of any themes on the marketplace anywhere that already come with some layout builder layouts perhaps using Bootstrap or even better some custom block types and TWIG templates that I could then embed predefined widgets already styled in the themes style into layout builder. Obviously I can create my own custom block types and create the TWIG templates for them, but because of time, I was wondering of any themes exist that already have this kind of thing baked into the theme with supporting custom modules to make it happen.

I was looking at a couple themes from Gavias at Theme Forest and they have created a custom content builder similar to layout builder to embed custom widgets into the layout, but it is proprietary and honestly a little clunky and doesn’t lend itself to translate the content easily which I need to do, but since that theme comes with supporting Drupal modules to interact with his proprietary content builder I was thinking maybe someone might have done the same thing with layout builder.

Here's a couple themes that I was talking about from Gravias Themes.

https://themeforest.net/item/uxima-responsive-multipurpose-business-drupal-8-theme/23449596

https://themeforest.net/item/facdori-factory-industrial-business-html-template/23454614

I know layout builder is still fairly new, so there probably isn’t a ready built theme with this kind of stuff built in, but I figured I would ask if anyone new of any before I spin my wheels making all the layouts and custom block types and TWIG templates to embed in the layout builder myself.

THANKS