Get rendered CSS for a single block

Hi,

I need to find a way to get the rendered CSS for a single block.
We build a lot of reusable blocks in our setup which contain GenerateBlocks like containers etc.
We are injecting the HTML of these blocks dynamically into our page content, based on a special targeting like users language, browser width etc.
We have run into the problem that GenerateBlocks doesn’t contain inline styles, because they are stored for every page.
Since we don’t have them on our pages, because we inject them dynamically, there is no rendered CSS.
Therefore I’m looking for a different way to get the CSS from GenerateBlocks. Is there any way you can provide a function which returns the rendered CSS for a single block? Based on block-ID or block-HTML.