The main bit of STEP that I designed is how to model properties that depend on other property values, it doesn't get much use in CAD systems right now but there

The main bit of STEP that I designed is how to model properties that depend on other property values, it doesn't get much use in CAD systems right now but there does seem some interest in getting it better used in the future. Another area of current work is in adding UUIDs to a model so that after doing a round trip from STEP into a proprietary CAD system and back to STEP you can work out which bits of the model are new and which not. This could be useful for parts libraries as well.