I have removed as little as possible out of the firewall to clear the carb, needs a bit of finishing/ tidying, But seems far less than other examples I’ve seen. Did you have any issues with heat from the exhaust? I have removed a little bit to clear but wondering how hot this will get and whether I need something more heatproof. I have cut the cowl and considering this had already been cut by the previous owner I think it has come out pretty well.