REW question -- judging SPL and Impulse graphs

Having established an optimal LP and Speaker placement, I am actively taking many sweeps of my room with REW to judge the efficacy of different treatments. This is a question about how to compare SPL graphs against each other and how to compare Impulse graphs against each other.

Regarding IMPULSE, I understand that a critical range of impulse responses in my room lies between 3-13 ms or so. So, after many sweeps under varying conditions, I'm trying to judge one impulse graph against another. In some cases, it's easy to see right away whether one graph is better than another; as I overlay them, I see more peaks, higher peaks, etc.

But in other comparisons between Impulse graphs, it's not clear which is better. QUESTION: Is there a tool in REW for estimating the area-under-peaks for a particular scan? This would help me quantify how one delimited impulse graph stacks up against a (close) competitor.

Regarding SPL graphs, here I have a similar problem. I recognize that in treating a room, the key is to get the bass region corrected, first. 20 Hz - 300 Hz or so. Looking an "all SPL" graph containing many sine waves, I see (for example) that Scan 1 has a big null at 135 and a modest null at 180 and Scan 2 has the reverse. Or Scan 3 has a big peak at 80 but modest nulls at 135 and 180 and Scan 4 has a modest peak at 80 and bigger nulls at 135 and 180. Which scans are better? That's the conundrum.

I realize that I may just have to listen to music at these various, competitive condition to tell.

I also realize that some scans may be differentiated by how easy or hard to treat one problem is vs. another.

I ask this "how do I judge one scan against another" not because listening or treatment are not relevant tools, too -- I get that -- but because I need to at least use the REW graphs to narrow down my options, if possible.

Thanks for any suggestions or advice.