Grrrr christa, now you’re making me research...GAH
Kidding aside I see your point, though that which was presented in the link, isn’t particularly helpful since it doesn’t explain what the measurements are. They say “as a percent”, but as a percentage of what?
A quick search finds tables and graphs that give more informative quantifications, mg/gram for example. They correlate with your table data, but are clearer.
That said there’s a more cosmopolitan point to be made. I’m not a tea conneseuir and took rooibos as a brand of tea, not a KIND of herbal tea.
Others reading this thread who ARE tea affecionados and say “oooh, rooibos is fine, I’ll feed black tea” or other kind of tea.
A quick search shows herbal teas are all over the map in their oxalate content, ranging from none to as much as black tea.
So the larger point is with teas, exercise caution, and you need to do your research on oxalate content before feeding. Black tea? NONONO! Oxalate free herbal tea? Sure. Why not, no harm.
Or just avoid the issue altogether and don’t bother with teas since parrots drink so little anyways

Plus, come on! my bird BATHES in his bowl whether I want him to or not. Not sure I wanna come home to find he took a bath in tea.