Currently, you are able to use the ctrl+B command on a text style to apply the bold font weight to a desired string of text without breaking the text style.
However, if you want to apply other font weights like light, medium, semibold, or black, you must either create a entirely new text style (which can add up quite quickly) or detach the text style and manually change the weight.
A way to apply various font weights without breaking the style (in the same vein as applying different styling like bold, underline, and italic) would be extremely helpful in increasing a design system’s adoption and flexibility.