I use to love Back to Mac, but I know they got rid of that. Would I be able to connect to direct attached drives via the Mac mini for local video editing? Any idea how that would compare with a NAS? In this search, I had started to think about a Mac mini with a Raided drive hooked up to it. I have been looking at a higher end Synology with 10gbe for editing and faster transfers. I've been using a synology was (DS418play) for archiving and light editing but its not really as consistently fast as I had hoped. So I agree, the internal SSD for storing shared files in this situation, very bad idea. With the setup you propose, you risk slowdowns due to the SSD being over filled and over taxed, and using an external T'bolt RAID will NOT slow you down at all, but actually give you better performance overall. Mac Mini as a file server only makes sense with a T'bolt RAID which is MORE than fast enough for what yo need, and leaves the internal SSD to not get bogged down. I've spent over 20 years as an IT engineer/manager and what you're proposing is not anything I'd have ever suggested to anyone. That many editors will eat it up very fast. Using the internal SSD is also a bad idea due to limited storage space.

Same reason we use secondary drives for media and Libraries on a standalone system. It must be left alone to do work for the OS and the active apps.

But pile up all those reads/writes from other connected editors, that internal SSD will crawl. Technically it is faster doing one operation.

Mac mini 2018 video editing