I shoot 18 x 22" tintypes and ambrotypes. No film yet, but I do have a film holder. I use either a 24" Red Dot Artar or 16 1/2" Dagor, The 24" is a barrel lens that I use Waterhouse stops in, the other has an Ilex shutter. As you know, wet plate emulsions are terrifically slow (sunny day = 20 seconds at f32) so I shoot landscapes. DOF is a major issue at this plate size.
I'm impressed by your site and your products - in fact for years I used a Packard shutter behind my lensboard when I was shooting with a Dahlmeyer 20 x 24" lens (also Waterhouse-stopped).