Hi there, this is Roger from CoreMelt, feel free to chuck questions at me. You don’t need 10.5 to run Veeyou or FxFactory 2.0.3 they both run just fine on 10.4.11
You also don’t need to purchase Fxfactory, you install the “plugin engine” which enables a range of plugins from CoreMelt and other Noise Industries partners.
Please note you don’t have to install FxFactory to use the After effects version, (mac only) it’s a completely standalone set of plugins.
sorry for any confusion