Per my earlier post, I've been using a Pi Zero W with Chromium in a kiosk mode to display Grafana on a TV. Not sure if something changed with Chromium in the December 2020 release, but it wasn't working when I tried to do a rebuild. So, I found an alternative and I've been having a lot of trouble getting it to work. I think I might have figured it out though, and it's easier than the previous method.
https://reelyactive.github.io/diy/pi-kiosk/ has a nice write up and it works fine, except for one thing. Grafana puts parameters in the URL that use escapable characters, like &kiosk. So, you must add "" around the URL. Took longer than I care to admit to figure that out.
I'll post a reply if I have any issues with it.