It is definitely possible to do regular "non-TCP" Appletalk from BasiliskII (and Sheepshaver I imagine, although I don't think I've done it; my experience with doing it from BasiliskII is *very* old) but I don't think the default way they set up the network when you're running on a macOS supports it; you need to either set it up as a direct "bridge" to a physical Ethernet device or, if you use the conventional TAP network, set up some Appletalk routing between the tap and the physical interface that pretty much requires using Linux as the host. *If* you can get it set up like that then it should show up in the Choosers of the machines behind the Appletalk bridge. (I assume you're essentially using the host that generates the files as the "server"?) Bridged networking should also be possible with QEMU, I believe... maybe I'll take a crack at setting that up, I think I have a classic MacOS image on my MacBook.
What might be *slightly* more intuitive to set up would be to use a separate file server from the machine that's running the emulator that generates the data files to stage them on. Either an older MacOS that still supports classic Appletalk (support for that lasted until... 10.2?) or NetaTalk would let you set up a server that works with both classic Appletalk and Appletalk-over-IP, and connecting to an Appleshare IP server works out of the box with the standard BasiliskII/Sheepshaver configs. Then the workflow would involve mounting that share on the emulator, either dropping the generated files into it manually or, if possible, setting up the program so it generates them directly in the share, and accessing *that* from the IIsi's.