I'm not sure if this should be "improvement" or "new feature"...

Can we get MAEviz to construct a spectrum similar to USGS/NEHRP and HAZUS?

I'm thinking something along the lines of an if statement that checks if the Sa at the highest period is less than the Sa at the next lowest period. If it is, then draw the spectrum similar to USGS/NEHRP, with Sa proportional to 1/T at the tail. If not, the current method should be fine.