I recently watched a podcast from some of Google's Chrome devs that explained some of the extremely weird and unpredictable behavior of IFrames across different browsers.
https://www.youtube.com/watch?v=W6lvQvdeF8U
The TLDR is that IFrames break the back button, it's also how ad popups manage to make the back button always keep you on their site.
If browser devs all decide to deprecate IFrames, at least my back button would work better on SysAid...
