Advice needed, how would you build for a Figma plugin.

[stubar]

I am currently building a Figma plugin and bundling with Parcel. Details about how the plugins are executed can be found here.
https://www.figma.com/plugin-docs/how-plugins-run/

So far I've been using

"targets": {
		"browser": {
			"isLibrary": false,
			"includeNodeModules": true,
			"context": "browser",
			"engines": {
				"browsers": "Chrome 60"
			}
		}
	},

It kind of works but spread operators aren't working. I can only think this is because the code is running in a quickJS web assembly sandbox. What I would like to do is target a pre spread chrome version such as 45 however when I target anything less than 60, parcel's output starts to use import commands which also doesn't work.

Any advice here would be greatly appreciated.