UCI documentation for DSA?

Is there any comprehensive documentation about how to use the newer DSA options in UCI? I haven't been able to find anything more than snippets here and there, and they're not described e.g. here https://openwrt.org/docs/guide-user/network/ucicheatsheet where I'd expect. The closest I've found is https://openwrt.org/docs/guide-user/network/dsa/dsa-mini-tutorial which has some examples but I'm really looking for some more exhaustive documentation about what the all the options are and what they mean.

Clear. concise, and reasonably complete documentation is missing.

The above links allow one to make some guesses about some of the syntax, but seem to make the assumption that someone is configuring with LuCI. There aren't sufficient examples present to be able to guess at the syntax for things much more complex than the "standard' wan/lan/guest setups.

Where are the design specs for the syntax?

Working from a complete spec would be best to resolve this

https://openwrt.org/docs/guide-user/network/vlan/switch still exists, and dates back to 2015 or 2010 It should be considered for removal.

I know first-hand that https://openwrt.org/docs/guide-user/base-system/basic-networking was expanded to cover swconfig-style UCI.

is not really sufficient to write config with.