Forum Discussion
This is unfortunately a limitation of both APM RDP clients, whether ActiveX or Java. You can't resize them. The Active X client is better than Java, but it's aging and starting to look fairly bad compared to the real Microsoft client. With Microsoft's new Edge browser on Windows 10 dropping support for ActiveX and eliminating that option, I really hope F5 puts some investment into this area soon, assuming there's any way to improve upon it in these days of the NPAPI (Netscape Plugin API) being removed by browser makers.
What works for some applications (though it has its own set of drawbacks) is opening something like an RDP app tunnel after APM authentication, and allowing users to use the real Microsoft client to access the backend resource. You aren't really proxying the connection in the same way, more like passing it through by tunneling that port back to that resource, but it can be a good solution in some cases because it allows use of the Microsoft client, but denies use until APM policies have been fully met.