@FarmerTy can you share your observations? which high end nems make a deadly mix?
(btw, we saw your rusty scissor fragging of expensive btas on youtube, crazy!)
I'm no expert but I do keep a lot of "high end" aquacultured anemones. Based on my observations, I do not believe it is chemical but more so a bacterial incompatibility. Whether it is due to newer imported anemones bringing in bacteria that is incompatible with aquacultured specimens or whether it is due to the decreased resistance to disease that aquacultured specimens may have developed.
Either way, my personal opinion is you'd be crazy to mix a Colorado Sunburst with a wild BTA, a rainbow, Sherman, or black widow. There have just been too many cases where the CSB slowly over a period of a month declined, had spots on the tentacles, went into hiding in the shadows, had curled tips, lost color, and had issues inflating.
Most of the time, the removal of the offending anemone with a cipro treatment (antibiotic) corrected the issue if caught early enough.
That all being said, I have 6 varieties of cultured anemones in my system together... Mak Inferno, Arizona Sunset, Colorado Sunburst, CC Supernova, CC Sunburst, and Reefwise Lemondrop. While I can't say it'll work on everyone's system, it works in mine. I did have to treat the Reefwise Lemondrop when it first entered the system as it had evidence of a bacterial incompatibility when first introduced into the system. Once treated and put right back into the system, it was fine. Another bit of support to my hypothesis that it is indeed bacterial and not chemical warfare as the cipro remedied the situation. If it were chemical, the reintroduction of the Lemondrop should have resulted in the same issue again most likely.
Again, this is just discussing aquaculture anemones mixed with wilds, rainbows, black widows, Sherman, and rbtas. There have been plenty of people who have mixed all of the above and been fine but I would highly suggest not adding a cultured CSB into that mix. It'll be the quickest you ever lost $1500 in your life. [emoji4]