App block in an iframe
This demo runs the price by position LED neon customiser in the Sign Customiser app block with Use iframe (experimental) turned on, so it loads in an isolated iframe from web.signcustomiser.com, apart from the theme's styles and scripts. Turn it on when theme styles break the customiser's layout, or a theme script or page builder stops it loading. If the normal app block works on your theme, leave it off.