Rob,
Great post.
That is exactly what I did to analyse the 4345 some time back...
When measuring in the near field (less than 2 metres), vertical height will display not only driver vertical polar angle but also crossover and driver interaction. Therefore I tend to take a series of measurements at different heights often with one driver turn on at a time then all on (others padded back) and then an overall measurement further away to interprete what is happening. One measurement tells you very little.
Unfortunately most of us don't have the luxury of a wide open space or a vacant roof top like JBL.
I've been doing Pulse and MLS measurements for a while (about 7 yrs ) at home and obtaining useful data really is an art form when attempted in the home environment.(its not always practical to relocate a 200+lb loudspeaker)
Aside from mic position I found the most intuitive measurments by management of the main room reflections which are often the floor and ceiling.
Placing pillows or bedding covers on the floor half way between the speaker and the mic is useful in contolling floor reflections. Acoustic tiles above the system suspended from a light fitting is also usful on controlling ceiling refections which might otherwise be interpreted as a peak or notch on the amplitude response.
Some accoustic tiles at the sides can also assist in removing a lot of junk in the un smoothed curves.