[NTG-context] Various setuptolerance settings within a single document

Dear All, I'd like to apply 'verystrict' tolerance as a default value, which would be overridden by less strict values in several specific paragraphs with tricky word combinations causing problems when hyphenating. But when \setuptolerance command is used multiple times, the last one seems to be active only from that place on. When settings is wrapped by \start \stop commands, it seems to be ignored: \start \setuptolerance[tolerant] %text \stop Is there any way how to achieve this or do I have to use the lowest required value for the whole document? Thanks, Jan