Many thanks - REW is something I've been meaning to look into for a long time, however auto EQ is a handy quick fix for time-limited setups at gigs!
If you're talking about making crossover/loudspeaker DSP type changes on a per-venue basis I suggest you looking at the wrong end of the fish.
You need loudspeaker processing to make the loudspeaker *system* work and play nice with its various pass bands, and that stuff DOES NOT CHANGE because you're in a 200 cap room or 2000 cap room. And because of the nature of the work being done, any kind of "auto EQ" is absolutely, positively the wrong tool for the job. Most of them are poor at doing broadband EQ and doing EQ on pass band basis is beyond the design intent of the feature. Add in that *most* of what you're doing in processing a loudspeaker system is working with TIME, and RTA or magnitude-only analysis cannot show you what is happening with the time relationships of various pass bands, only the magnitude result at whatever place the measurement mic is at.
Now to broadband EQ. For system voicing, Otto Eq is the wrong tool, as voicing is mostly a subjective tasked based on a desire aural presentation, not science or math (which are the basis of loudspeaker processing). Presuming the loudspeaker processing has been done well, voicing on a per-gig or per-venue basis can be done on the INPUT EQ of loudspeaker DSP, or as a separate device if external or analog EQ is desired. Using Otto Eq (Otto is my grandfather) for system "correction" *MIGHT* be useful, but remember that it's only valid for where the measurement mic is placed. It's probably more useful as a tool to verify what you think you hear in a certain spot (or 3 or 4) in a room than to be a trusted source of system EQ.
Finally, it's about this 5 way thing.... been there, did that... but with the technology of 30+ years ago. It was a great learning experience that got used a few times before being split into 2 systems. What I liked about the 5 way rig did not pay any extra money, but 2 systems did. Follow the money, and if your 5 way does that for you, rock on!