That sounds great! Now I’m really looking forward to putting in the effort to do lettuce in containers.
I thought of another benefit — gophers won’t have nearly as easy a time destroying everything if it’s in containers. Let the pests go ruin someone else’s hard work. :-)
For me the no bending over is great. Here’s a good shape for getting a lot of lettuce.
https://www.lowes.com/pd/Style-Selections-22-17-in-W-x-7-05-in-H-Rust-Resin-Planter/1000175867
I have three similar about 27 inches long. This is the quickest picture I could find. Don’t need a drain tray if its outside. Just drain holes and I have at least a couple of inches of packed shredded straw under the garden soil. It’s more lightweight and at the end of the season they all get dumped on their own little compost pile. I reuse the next year and add some compost. Leaf lettuce doesn’t like to be crowded and likes good drainage. The shredded straw is great for that. The three varieties that do the best for us are regular romaine, Little Gem, and Red Butter Lettuce. If no rain I water at least three days a week, lettuce loves a spray.