Charly,
I know Barry likes to power his switches with their own transformer, however
I have been running my FT CC switches with track power on my Christmas layouts and they have been working perfectly and I have no DCS signal drop, granted I only have a a few FT CC switches right now, we will see what happens as I add more switches to the FT layout. With the voltage draw so small I do not think things will really change any. Try using the track power to operate your FT Switches, and see what happens,
if you get the same results I did, you are going to want some Command Control FT switches, they really are seriously cool, and running in this manner eliminates all the switch wiring, which to me is a dream come true.
PCRR/Dave