Citrix is no longer supported as a FAT Client for Development Purposes. Really, it hasn't been properly supported since 8.10.
However, using Citrix to publish Internet Explorer IS supported - by Microsoft and Citrix (as citrix is supporting the Browser, and JDE supports the web browser). Several companies utilize this to ensure that the browser is fully secured, to ease operational management of the browser, and to reduce traffic across their WAN. I have personally moved away from recommending this over the cost - but if the customer is a large Citrix user, then theres no reason not to run the JDE Applications through a browser that is being presented to the end user via Citrix. It works, and its easier for the customer to support.