Radio Group design in Figma
Set up your Figma designs to have as many radio buttons as you like by copying and pasting them from one of the MUI Figma files. You can style them however you like. Also, you can copy and paste whatever default states you'd like to see such as checked or un-checked but the defaults can easily be overwritten by code.
Once you've got your design finished in your Figma file, import it into Quest using the Quest plugin for Figma. When you see the component in the Quest Editor, click on the frame containing the checkboxes and go over to the right-side panel and press the plus button next to "Features". In the drop-down list, select "Radio Group".
From the pop-up, you'll be able to setup the radio group as a whole.