Thanks for all your input.
TomH. I probably wasn't clear. I wrote the new fact type in RM6.
I made a test database of about 5 names and entered the census information for each, using that US Census fact I added ([Person:Given:Surname] ([Desc]) was enumerated in the [date:year] US Census, [date], at [place:plain].).
I just exported the info from RM6 to a GEDCOM. I imported that GEDCOM into Legacy, and PAF. Everything about the Census was imported. Date, Place, and the description (1, single, grandson of head of household JISwartz). Everything was there.
BTW, When RM6 did import the Census data from Ancestry.com and put it in a Residence fact, you can tell it's data by checking the source. It states that the source is the 1940 (or whatever) Census.