URL Forwarding and Masking

Technically yes you could do this with an irule sideband connection (or if your backend server has some method to load resources from other web servers and serve them based on the url it receives) and creative usage of the rewrite profile (which doesn't by itself require APM reference: https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-implementations-11-6-0/24.html). This would be a fairly complicated endeavor -- especially the sideband version -- as you'd basically be reverse engineering APM portal access. But sure, in theory, you could do it :)