I think this issue may be caused by a memory leak (or some other memory issue). The same CTD can be observed at many other addon airports in the sim. This thread includes reports from many others who similarly CTD on Xbox within only a few minutes of launching the sim at certain addon airports.
The problem only seems to be triggered by “heavy” addons - content with lots of detail. The problem may be exacerbated by animated objects within these addons. Asobo’s KDFW includes an animated tram, and iniScene’s KBUF (which also CTDs) includes an animated radar tower.
I think the observation that these issues likely share the same root cause is a notable one. If that’s the case, this is an issue that Microsoft/Asobo needs to take responsibility for, since it isn’t exclusive to third-party addons, nor is it a one-off problem that’s unique to DFW. The sim simply seems to CTD when it is overwhelmed. In other words, this is an issue with MSFS itself, not the addon content.