There was a discussion in 2010 about the maximum library size. I need to re-visit this on behalf of a client with a 6TB library.
Everything in one file helps with finding things but I worry about the size and corrupting databases. Moreover restoring a 6TB library from a TM backup will take time.
Perhaps there is a better strategy? Digital Asset Manger options?
There is no maximum catalog size in Lightroom. It doesn't matter how many TB your photos take up, your photos are NOT stored in the LR database.
If you are worried about corruption, then the solution is to make regular and automated backups of your catalog file to a different physical disk. (And make backups of your photos too...)