I managed to add ability to open multiple desktops in separate windows for test_app_server. Application can be started in desktop by command like TARGET_SCREEN=5000 Screen &. If screen id is different new window will be opened. It will help to add multi-screen support without waiting for accelerant API change. I also managed to add remote HWInterface in test_app_server.
When working with test_app_server I experienced some problems:
Tracker crash at start because get_key_map returns NULL keymap. File open dialog is working.
There is conflict between registrar and test_registrar. Applications started in test_app_server are displayed in host system Deskbar instead of test_app_server Deskbar sometimes. When exiting test_app_server, host system Deskbar quit instead of test_app_server Deskbar.