Hmm, I didn't realize you could use chrome extensions w/ Kiosk mode, I had discounted that option. Perspective desktop doesn't allow iframes just like any other browser, see this thread:
This isn't a bad idea, I see they can be had at Best Buy for $152 at the moment.
In the end pturmel's suggestion from the linked thread above to pursue it on the web application side was the way to go.There is a way to grab URLs from Tableau so they can be embedded. Now, this isn't a universal solution, because not every website allows that, but it works for me for now. I may try the x86 mini PC w/ Linux in the future for sites that simply don't allow iFrames.The Tableau user authentication aspect has been an issue as well, my Raspberry Pi doesn't want to remember the login credentials, and our licensing setup with Tableau doesn't allow anonymous users. Perhaps the Kiosk mode deserves another visit...