Trying to use Roboto Medium as a font after importing it using 'https://fonts.googleapis.com/css?family=Roboto:400,500
Am however unable to select it using font weight in style attributes. Can I only use this by setting up a CSS Block?
So it's not really the limitation as I described, it's using the font-weight properly.
With some testing I was able to import that font and then set the body element to use that font-family. With a clean slate project I had dragged in a Hero component to test with.
But with all the base styling from bootstrap, you have to pick a specific element that you want to override. And you have to use correct font-weight coding, such as medium not being a valid value. I'm not sure what you are trying to accomplish with medium, as I would assume medium being the default which is value 400 or normal. With the link I posted you should get a better understanding of correct font-weight coding.