I haven't, I'm afraid. But this made me remember a discussion I heard on a podcast recently where someone was raving about developing tubes for 4x5. I've not seen one, but it sounds like a simple tube that takes one sheet and you can float in a bowl of water (to stabilise the temperature).
Yes, tubes are common. There's a few ready made ones you can buy. Some have ends so, once the film is in you can use them in daylight, others are just a bit of pipe that you roll around in a tray of developer etc. in the dark.
I have some tubes I made some years ago when I first tried LF. They can be used in daylight which I need as I don't have a darkroom anymore. But I was looking at tanks that can process a few sheets at the time. Stearman make two, one takes four sheets and one takes 6. They can also be used for glass plates or tintypes, using different inserts, which is something I might try at some point.
