[specialist]

Thanks. That looks bitchin. Will check it out.

Looking at its stock UI, I'm reminded of one of my basic grievances with CADD of the AutoCAD model:

I hate layers.

When doing architectural plans, which layer does the electric water heater go onto? 'ELECT', 'PLUMB', or a special case 'ELECT-PLUMB'?

Much better would be something set based. (Today we'd probably call them tags.) Instead of toggling visibility, views should be queries.