In case anybody is interested in organizing the chapter list, each volume is four chapters long...easily determined by which chapters the colored images appear (ch1,ch5,ch9...etc).
Vol 1: 1-4
Vol 2: 5-8
Vol 3: 9-...you get the idea.
Chapter 9's cover is from the monthly magazine version, but is also used for the cover for the 2nd tankobon (ch 4-8).
source:
Vol 1 on Amazon.co.jp:
https://tinyurl.com/ybbn9csp
Vol 2 on Amazon.co.jp:
https://tinyurl.com/yc3boa6l
Or you can leave it the way it is in case you're not planning on redoing the tankobon versions if you're already satisfied with the magazine versions. Otherwise, you can use the Vol. 1--naming convention exclusively for the released volumes. Just a suggestion.