Allen Miu's space label code has been integrated into acad2ug. Currently, it spits label information into a *.label file in an obvious format.
The question now is where REALLY to store the space label information,
and at what point in the pipeline it should be introduced. I think
there are 3 options:
255.000000 590.846000 0.000000 "251" "OFF"
Which could be translated into a unigrafix vertex like this:
v @251@OFF 255.000 590.846 0.000;
ug2iv would read all vectors with an ID starting with @, and make an iv label with the appropriate text.
The code's pretty flexible, so let me know what you'd like to see.
-JMB