Wasn't subscribed to admin until now, so sorry for not replying to Jens' email directly. 

It may be worthwhile for SG10 to meet for at least a short session, if we can get people to show up. We have two papers (mine to add all the macros and address multiple NB comments, and Ben's to discuss macros for freestanding) but also we could use a discussion on how to rev macro versions and what to do about constexpr (both language and library). There are differing opinions (and at least one NB comment).