Dropping feds instead of tapping gifts when visiting neighbours

I'm not sure about all limits (I've read in another blog that your own town can have a max of 20 feds at a time but most of my neighbours don't have feds yet).

I haven't encountered any limits other than the 3 per town limit when visiting friends. After 120 feds were dropped, I only receive 1 FP each and no presents.

As Brevis noted, I only dropped feds in towns where they were far enough in the quest line to support it. For me, the fed icon was missing if they weren't far enough.