Not quite so. Omnisphere installs by clicking the installation file. It places presets and tables in the correct folders automatically. Omnisphere has the same kind of browser information as HALion only more thought through. It even tops the information by adding graphics (sometimes the graphics tell a story too) and/or much information on the source of the patch. Where HALion is overwhelmingly complicated, with a lot of completely unnecessary buttons, Omnis is simpler and faster to use. Steinbergs Mediabay is something that some like and some dislike. I dislike it. I have been working with relationship databases since 1993 and to my knowledge the Mediabay does not hold up to standards of a “great” GUI. It is a programmers GUI and not a user GUI. A “great” user GUI you can find in Omnisphere.
And btw, the procedure you described for installing 3. party stuff in HALion, did not work with the presets in question.