I, too, tray develop. Six sheets at a time is my preferred maximum. I use deep Paterson 5x7 trays for 4x5 film and rarely have a scratch. 25+ years of doing it this way. Maybe my experience will help you decide.
Tray developing requires little in the way of expense and materials, but as a tradeoff needs skill and dexterity. You need to practice with scrap sheets for a while with lights on and then with lights off (eyes closed) to get used to it. Scratches when beginning are more common, but the learning curve is fairly quick. Practice with real solutions; water, developer, stop and fix all have slightly different feels, and shuffling in the respective solutions is somewhat different.
Avoiding damage also requires that you pay attention during the entire processing, from pre-soak to the washer. If you let down, you're liable to scratch a neg.
I have found that keeping the stack neatly stacked so corners are not sticking out helps a lot to avoid damage. I also try not to drag the film I am shuffling from the bottom to the top of the stack across the bottom of the tray. This will result in small scratches on the base side of the film if the bottom of the tray is at all rough.
I develop emulsion-side-up. Step one is a pre-soak. If you don't pre-soak, the sheets will stick together and be very difficult to soak apart. I immerse each sheet in the pre-soak and wait 15 seconds or so before adding the next to avoid this. If sheets do stick together, just be patient, they will soak apart in 5-10 minutes. At this point I turn one sheet with the code notches the opposite orientation of the other sheets and make this "sheet one."
After the pre-soak, I gather the films and fan them in one hand like a hand of cards, with sheet one on one side. I immerse them in the developer one-at-a-time, over 30 seconds, beginning with sheet one. I then agitate by moving films from the bottom to the top of the stack, going through the stack once every 30 seconds during the first half of development and once every minute for the second half. I turn each sheet 180° when shuffling. I keep track of sheet one so I can immerse the sheets in the stop the same way I did in the developer.
When agitating the film, be careful to lay the film down flat on the surface of the solution so as to not dig in a corner. It is also important to not push the film down into the developer solution too quickly. Gently push one side down and guide the sheet slowly to the stack. Too fast causes turbulence around the edges and results in denser edges.
Stop and Fix, same procedure. I turn on the white light after two minutes in Rapid Fixer and continue with the lights on.
Everyone develops their own idiosyncrasies when tray developing; you will too.
Best,
Doremus
www.DoremusScudder.com