Every time we get a bug report we look at it immediately regardless of the airport/addon. When we heard from you about having performance issues with KSUU, we found and XBOX S, flew and taxi around the airport and we did not have performance issues at all. Microsoft marketplace team also does testing (flying around, taxing, looking at textures and models, etc) and they found no issues either.
Here is the video we recorded in an XBOX S after you reported performance issues:
KSUU is our top selling addon and we have not heard any other performance or bug reports. Like I mentioned in our previous conversations, it could be related to your xbox or the MSFS installation specifically. We looked in the SDK and debugged it and could not find any problems with the models or the addon in general.