[NTG-context] more stretch

Thank everybody for indispensible help, esp. Wolfgang. I owe yuo a beer :) My project should be completed today, so it is probably one of the last questions. I have set up \setupalign[stretch], after which my document looks far more justified (no ragged right text edge). However, in some difficult situations I still get the problem, as shown on attached shot. Moreover, TeX compains about a lot of overfull hboxes. How to instruct TeX to relax and allow more spacing between words (or more stretching?) Best, Vyatcheslav