Hi, I've just been reading this thread and I thought I'd follow it up. Got the RGG rules pdf (thanks rbilabronze) and then went to the HiG website to see what they said in German. At this webpage
http://www.hans-im-glueck.de/79.0.html they give a link to the German rules in PDF format.
I know a bit of German; the HiG rules are brief and do not mention anything beyond the second expansion; I could find nothing to suggest what is written in the RGG rules.
As I mentioned before, I know ONLY a LITTLE German and I would translate the HiG rules thus:
(Specifics) further rules in relation to the expansions:
First expansion: The large follower may also be placed in Carcassonne. When he is placed for scoring, he scores as usual as two followers.
Second expansion - merchants and builders: when a player with a builder gets a double-move and fulfills the required conditions at each part-move, he can place a follower in Carcassonne at both part-moves.
I plan to write to HiG to seek clarification on the remaining expansions. I'll post more when and if I get a reply from HiG.