RE: strange crashes
If your using different receivers in each plane, then the common link would be the transmitter. If I'd have been in your shoes, I wouldn't have flown the radio without having it checked by Spektrum after I'd seen two similar failures!
When we had to build the airplanes we flew, I guess we were more cautious about risking all our hard work, with a questionable piece of equipment. I know that Spektrum is receiving some bad press at this time. This should have triggered a more cautious approach for you! Sorry for your run of bad luck and good luck getting a fix!