Actually UD, we use 4 bar fills in arabic music all the time, they are used as "stimulators" to the audience.

What I usually do is seqeunce the fill in as a pattern, this way I have actually a 4 bar pattern and I can use 4 different ones (A B C D in X1), and on top of that you can vary those by using the fill ins...so its fill ins within fill ins. When ever you need those fill ins, simply select that pattern.

hope that helps