Reactive web-  SortSite is not rendering the page properly

Has anyone successfully used SortSite to do 508 compliance testing on reactive web pages?   When I attempt to scan our URL the page is rendered like it is in IE and everything fails.  (Which is expected because IE is not supported)

Our corporate 508 tool is Sortsite so I'm trying to find a way to make it scan as if it were a normal Chromium browser.   Anyone know if this is possible?   If not, what tools have you used to do 508 testing on reactive web apps?