#2 the idea behind steampipe was to leave the default folders alone.
For the OP, there are technically three places for maps
#1 tf\maps: this is for default maps, leave this folder alone
#2 tf\download\maps: this if for maps that you downloaded during play, e.g. the surf server you are on switches maps and you need to download the new map.
#3 tf\custom\FOLDER\maps: this is for maps that you personally have downloaded from places like gamebanana, e.g. the maps for this season of open.
The only caveat is that maps in the tf\download\maps folder will not show up when you try to create a server through the gui.