So, in your case, where you have one big frame with animations that you want to export as a GIF directly from Figma, it seems like a bit of a challenge. Currently, Figma doesn't have a built-in feature specifically for exporting a single frame with animations as a GIF.
However, I can offer you an alternative suggestion that might save you some time and effort. Instead of recording the prototype preview page and editing it in Premiere Pro, you can try using a screen recording tool that allows you to capture just the Figma canvas with the animations. There are many screen recording options available, such as OBS Studio, Loom, or QuickTime Player (for macOS).
By using a screen recording tool, you can focus solely on capturing the animations within the frame and save it as a video file. Then, if you still want to convert it to a GIF, you can use a video-to-GIF converter tool or an online service to achieve the desired result. This way, you can skip the extra steps of editing in Premiere Pro.
I hope this suggestion helps!