Thanks for the responses, guys.
There does seem to be an issue with Steinberg VST3 plugins such as Retrologue and Padshop. These synths rely on the DAW's preset browser for managing and loading presets. The problems is, as was mentioned above, the Steinberg standard is to use the .vstpreset suffix for presets whereas Cakewalk have chosen to use the .fxpreset suffix instead. This means that I cannot see or load any presets for these synths.