Unless done too often, from Z to L not so "alarming". Imagine you have a short time to get out after accomplishing your duty and then see how you can reason in your consequent L application. To my knowledge, many have done so but some needed an address and proof of some cash at hand (in bank account). Having said this, however, I agree with you that PSB may be alarmed by agents who arrange such visas so often. This is why I suggested a steady employer instead.