The to-do list

OMNI completion for in scope variables (including display of library function signatures). This will probably get complicated because most times when you want completion you'll already have typed half a statement, and LuaInspect will find syntax errors when trying to parse the source text. scite.lua can just use the last known valid AST but luainspect4vim.lua cannot keep this around when executed as an external process…
Document g:lua_inspect_path option.
Check whether "core/SciTE: jump to definition now supports functions in different files." is interesting.
Bug: The plug-in sometimes warns Invalid output from luainspect4vim.lua: 'This is an unknown table field.'. Mixup between tool tip / highlight response parsing?!

Known issues

Dynamic highlighting using Vim's matchadd() function performs very poorly in large buffers -- so poorly that Vim becomes pretty much unusable until the user disables dynamic highlighting using :LuaInspect! (e.g. try editing luainspect/scite.lua using the Vim plug-in). I've since switched to highlighting only function names (instead of multiline call expressions) but that hasn't improved performance as much as I'd hoped...