I don't want to dispute the Agust theme warning but I'm not having any problems so far using the old themes. Of course use at your own risk.
The themes made before December , EFM (File Manager) does not work and many emodules, they are horrible, Systray, Siscon, TaskBar etc .....
Anyways, as you rightly said.
"using the old themes. Of course use at your own risk".