AGHatchett3rd obviously knows nothing about gedcom coding. Here's what a census tag from a gedcom file looks like:
1 CENS
2 DATE 1940
2 PLAC Normal, McLean Co, IL
2 NOTE ancestry.com indexed them as "Rull"
2 SOUR @S149@
There is nothing in the tag about the "role", so whether TMG calls the person a principal, a witness, or anything else is not relevant, and there is no logical reason why the census tag should not show up in the gedcom file under each and every person to whom it is attached in my TMG data file.
In TMG I have 5 census events for my grandmother, from 1900 to 1940: 3 as principal, 1 as witness, and 1 as resident. Only 2 of these were exported to the gedcom file, from TMG8 to gedcom 5.5 with "all events" selected. This is obviously NOT a limitation of the gedcom standard but a bug in TMG's export algoritm.