I've just noticed that new soi "always takes top scope". Why is that? Not knowing the discussion that led to that choice, I incline to the view that in a reformed Lojban there would be a new syntax that syntacticizes the left-to-right scope rule (so that clause structure is binary branching, as in Xorban), in which case you'd expect soi to scope over what it precedes. Most if not all tags (e.g. tense) could be seen as abbreviations of soi phrases, and hence you'd expect soi phrases to have the scopal properties of tags.
--And.
--