The issue with Vagrants is that they're rare and most people don't know how to spawn one reliably for themselves, making it seem impossible. For that to have been figured out in the first place, someone must have gotten gravelorded on purpose and looked for the relevant data, right? I don't have the PC version nor any knowhow when it comes to modding, but isn't it typically done by poking around into the memory and figuring out how to force their triggers? Like the gravelorded mod. It'd be pretty cool if there was a mod that forced Vagrants to always appear at every possible spawn location.