[NTG-context] Table-bug in lmtx?

Hello list following MWE gives a strange error "(interwoven alignment preambles are not allowed)" when processed with lmtx: \definetabletemplate[fosa][s0|xp(3.5cm)|lw(0.7cm)|xp(5cm)s2|lw(2.5cm)|] \starttext \starttable[fosa] \NC Cell 1 \NC\Use3[p(8cm)]{A longer cell}\NC\AR \MR \NC Cell 1 \NC Cell 2 \NC Cell 3 \NC Cell 4 \NC\AR \stoptable \stoptext No problems in mkiv. I think Use3 is the problem, but I'm not sure... Many thanks for your help Christian