Just posting to say that I have this issue also on 5.0-7232
The "Render to Main Window" check box always reverts to an unchecked state, editing the config file doesn't make any difference (changing RenderToMain = False to True still makes the option unticked but disables the tick box)
Edit - I've set Dolphin to use fullscreen and enabled "always on top" in an effort to hide the Dolphin UI as I run my collection from Launchbox on a HTPC and it works okay
The "Render to Main Window" check box always reverts to an unchecked state, editing the config file doesn't make any difference (changing RenderToMain = False to True still makes the option unticked but disables the tick box)
Edit - I've set Dolphin to use fullscreen and enabled "always on top" in an effort to hide the Dolphin UI as I run my collection from Launchbox on a HTPC and it works okay