Played around with my vinyl/cassette rip setup. My workflow (using my 2006 MBP running Snow Leopard) is basically: record using Audacity in Snow Leopard, split the file into tracks in a Windows VM running LP Ripper (I use the shared folders feature on VirtualBox, so the VM can see the file), import and convert the tracks to AAC in Snow Leopard's iTunes and then copy that over to my 2012 MBP's iTunes. The Windows VM was using Windows 2000, but it booted really slowly (slower than any real hardware I've ever ran Windows 2000 on), so I made a new VM with XP. You can still activate over the phone in 2025, I just wish the link Microsoft sends you didn't expire and you didn't have to call Microsoft to get it. Anyway, XP boots way faster than 2000, so I'm keeping that VM.
The main reason I use the 2006 MBP is because my analog to digital converter doesn't work on USB 3.0, or so I thought. Turns out that's only when using the bundled LP Recorder software. No such problem when using Audacity on my 2012 non-Retina MBP. Glad to see that the latest Audacity still runs in Mojave. Copied over my XP VM to the 2012 as well, and so far I haven't been asked to re-activate. Hopefully it stays that way. I ended up redoing a couple of my recent rips on the 2012 because I recorded them too loudly on the 2006. I have to say, it makes more sense to use the 2012 for this purpose than the 2006 since the 2012 is where I manage my iPod, but I do love Snow Leopard. Only way I could manage my iPod on the 2006 is to run patched Mountain Lion (10.8 is the minimum OS for my daily driver iPod) and even then I'm not sure if I can still sign in to iTunes on 10.8.
Even if I do stop using the 2006 for vinyl/cassette rips, I think I'll still use the 2006 for VHS rips because while the 2012 would be convenient should I ever want to put my VHS rips on my iPod, EyeTV 2 doesn't work on Mojave, so I would have to either buy EyeTV 4, downgrade to Mountain Lion (EyeTV 2 does have hiccups on 10.8, but was otherwise fine in the tests I performed using one of my 2009 Minis), or dual boot with Lion. So, I think keeping the task of VHS rips on the 2006 and sneakernetting the rips over to the 2012 is the best for now.