I know a lot of people have transited through TPE on separate tickets, but has anyone ever transited from a 'full service carrier' to a 'low cost carrier'?

2. Do LCCs even have a representative at the transfer desk?

3. I read on a separate thread that someone traveling on separate tickets on different alliances had their checked bags re-tagged with the help of the transfer desk. Can anyone confirm this? Is this only possible when switching from full service carrier to full service carrier?