Better conversions between growing zones would be a good start. Trying to mash Australian growing zones into the USDA ones is always going to be difficult, but the current map has Sydney and Melbourne in the same growing zone as the Simpson Desert which is certainly an interesting choice.

Looking pretty good! I'll pick nits because this is right up my straße, but it does work well for its purposes.

I prefer sorting by botanical names, but searching helps. Common names are too woolly & unreliable.

If you're feeling adventurous in the long winter evenings, you could nerd out with cross references. Have a table of plants buried somewhere that are called in charts of uses, growing seasons, etc.

You could calculate Growing Degree Days with auto-filling Base50 temp averages, or just give GDD info per plant with calculation instructions as the lazier option. Store GDD ranges & info in chart from above. I made a gnarly automatic GDD spreadsheet with home assistant filling temperatures for ornamentals and insects/pathology, but I never really look at it despite it updating every day.

Don't sleep on dyes, inks, etc.

You were creative in the spelling of perennial and comfrey.

Plants:

• Consider adding Urtica, Papavar, Lactuca, Galium aparine. Urtica dioica is extremely useful for food, medicine, fiber, & fertilizer - the stuff of legends. Corylus (hazel) is good for building and food.
• Not sure why you specify Symphytum x uplandicum and not just Symphytum spp., especially when your link points to S. spp.
• Salix is a fairly big genus, and most fiber willows are going to be in the shrub or understory layers (eg Salix lucida). Willow bark as medicine is overstated, and it is not analgesic, but it does reduce fever if you hate your stomach lining.
• Not sure what Lathyrus latifolius is doing in there - it's not edible, and I don't know of any uses for it other than pollinator fodder.

Source: A particular perversion for this kind of ethnobotany & a hort degree program that indulged it (suckers!).

This is a fantastic resource! Thank you!

The link for the pecan tree entry is no good. A few of the others from "the spruce" seemed to work fine though. May be a good idea to use archive links or otherwise copy the information in the growing guides somewhere so there's less potential for something breaking