Ok, that’s interesting. I’ll do some testings on my own with different phone brands when I have time.
Have you tried changing the following parameters :
rxlev access min
cell reselect offset
bts max power (or something equivalent, used in the C1/C2 criterion)
Since CRO is only used in C2, by modifying it and looking if it changes the No of bars, we might be able to guess if the phone is using the C2 or C1…
Let us know…