Thank you for bringing this to our attention.
The statement in the download center:
If you do not own HTML Editor 3, you do not need to install this version and should install CSS Form Builder 2.0.0.
should have been removed.
The support release _should_ be installed regardless of whether you own HTML editor 3 or not.
I have forwarded this to our webmaster, that statement should be removed from the download center shortly.