There are too many things in this post.
Alistair FrithYou are a brave soul...
Citrix over a 3G connection
Alistair Frithhehehe, agreed!
IP over Smoke Signals
Alistair Frithwell, according to Citrix protocols, if the client is (and it usually is) a native client, everything get's drawn on the server and the image is sent to the viewing device, this is (by no means) effective as it is getting all images sent from the server to the client. However, the application server would need to connect to the ActiveView Server to get the file and then the application server would connect to the PI Server to get the data, after refreshing it, the Application server would send it to the viewer client. All this will, definitively, take up a lot of time.
taking up to 2 minutes to load a display
I would suggest you look at your problem from different angles, measure the speed/latency/totals for the communication between everything involved in solving this requests. As it may be that you know there is a bottleneck, but it may not be where you think it is.
Again, depending on what Citrix Client you are using, how you configured your server and what device you are on, the PDI will not get to the Citrix Client, so the size of the PDI should not be a problem.
you also imply that the initial load time is only obvious when you are using the citrix client, does it do the same? on any citrix client and any connection? if so, you may be better off loging in into the citrix server and trying the application from there. I would blame the Citrix Server based on your problem description.
BTW, 3G networks, even with 2sec latency will serve a 600KB file in about 20 seconds tops.
With all that said, as this is more an implementation issue I would like to suggest you contact our regular Technical Support team... they would be better at handling that.
I sincerely believe the information provided will be of use to you.