There is a full installer for the Ventura public beta (as well as version 2 of developer beta 3).
It comes with product id 012-38308 and if you go to the sucatalog and search for the InstallAssistant.pkg with that product id you will find it is at
http://swcdn.apple.com/content/down...k7cxffui52ggv4xd3xbpwuuw/InstallAssistant.pkg
(see how the number 012-38308 is part of the link itself)
You kind of really have to know what you are doing to understand what I am doing here.
If you have no idea what I'm talking about, MrMacintosh made a website that makes this sort of stuff easier to find. The website is at
https://mrmacintosh.com and you can navigate there to the stuff you want without having to bother with product ids or sucatalogs.