1
Where to add an exchanger
The heart is on the exchanger page next to the rating and in every row of the exchanger catalog. There is no heart in the rate table: open the exchanger first.
2
What changes in the rate table
A red heart appears next to the name of a favorite exchanger, and the sort switch gets a third option, "Favorites", which moves your exchangers to the top. An exchanger cannot be in favorites and in the blacklist at the same time.