Notes:
Regarding the issue "uMatrix is causing iframe data to be mangled in the latest version of chrome":
I don't know what causes this -- uMatrix merely just add or modify a response header, as allowed by the extensions API. Until the root cause of the issue is resolved, you can mitigate it by changing the advanced setting disableCSPReportInjection to true in the new "More" dashboard pane.
Fixed:
noscripttags improperly rendered in XML-based HTML documents (report).