compilerOptions wont effect build/dont apply

[KevShe]

It seems that compilerOptions have no effect at all for the compiler.

export default {
	input: 'src/main.js',
	output: {
		sourcemap: true,
		format: 'iife',
		name: 'app',
		file: 'public/build/bundle.js'
	},
	plugins: [
		svelte({
			compilerOptions: {
				// enable run-time checks when not in production
				dev: !production,
				customElement: true,
				css: false,
				enableSourcemap: {
					js: false,
					css: false
				}
			}
		}),

Not a single option is taken into account while the build process runs.