I am breeding melleri (now it is F3 generation) and after my opinion CB are no more diffiicult to culture and breed like pardalis. They are active, "very intelligent" (suprisingly they remember for example very well where is "loophole" to escape). They are no aggressive and bring a lot of fun. My personal opinion is that they should be more widespread. Just one hint - there are many roach species they do not eat (I culture about 20 roach species so have material for testin) although they preferred food (except flies and soldier fly Hermetia) are Panchlora and other leaf roaches. But dubias they to not eat although Archimandrita same size yes. A bit mystery.
With imported animals I have had a lot of various problem but with next generation any. I lost my F2 parent animal due to "storm" - very strong wind, I never saw such in my life here, outside have fallen part of tree and destroy their cages so escaped and I did not found them living. Now I have just F3 but next year I hope I will have F4. My suggestion is buy CB melleri without fear, if you can keep alive pardalis you can melleri, too. But imported melleri thats roulette.