First of all, if your GBC is slow to load, make sure you are compiling your customization in prod (production) mode and not cdev or dev. See the entry for "prod"
http://4js.com/online_documentation/fjs-gbc-manual-html/reference/buildtool/configure_compilation.htmlOtherwise one technique that is suited to static pages, have a look at this example
https://github.com/FourjsGenero/ex_htmlpagegenerator That uses Genero code to build a static web page so you can re-use your existing 4gl logic to generate data, and you can also reuse the .css from your GBC or your .NET home page, depends what you want to look like. If you look through the README, there are some links to real world pages created using that technique, either on demand or batch. What you don't get with that technique is a running 4gl program, so you are not sitting in an INPUT, MENU etc whilst looking at that page.