Not sure if this is in the newer Audacity (I use 1.2.6), but as a suggestion, you
definitely need a smarter silence adder.
For instance, you might have a 128 bpm track with each measure being 1.874807
seconds. What I do currently is use that amount to add silence to each track where
that track’s loops (or audio) aren’t supposed to play (this keeps the loops aligned
This works well, but sometimes I end up with, say 8 measures of silence needed
and I either have to figure out the math, or repeat add silence until I get the
track up to the point of adding the loop.
It’d be nice if there were some sort of calculator on the silence adder, say an
entry box for a multiple [1.874807]  then [1.874807] 
That would be wicked smart.