The main issue with SeaFrogs domes is that they use a fixed port extension. Basically, the reason that you use a dome port is that when light rays pass through the water/glass/air boundary at an angle, they refract (bend) which leads to aberrations and loss of image quality.
If you shoot through flat glass, then anything that isn't directly in front of the lens suffers from this, and the more you go away from center, the greater the effect is. However, if you take the entrance pupil of the lens, and place it at the center of a hemisphere of glass (or acrylic, or any other transparent material) then, from its perspective, everywhere it looks it gets a plane of glass that is perpendicular the direction of light rays that reach it, and thus no additional refraction occurs.
The salient point is, for this to work, the entrance pupil must be placed as close as possible to the dome's geometric center, and thus on all the port charts that manufacturers publish, you see the recommendation for specific port extensions.
For example, in case of Sony 12-24mm f/4 lens, Nauticam recommends 75.5mm worth of extensions, while for the Sony-Zeiss 16-35mm f/4 they recommend 95.5mm with 230mm glass fisheye dome or 85.5mm with 180mm N120 dome, or 80mm with 180mm N100 dome. The differences are due to both varying lens geometries and varying port geometries, as different ports rated at the same size can have different curvatures, as they are effectively same-size portions of different-size spheres. For example, if you take a 180mm diameter sphere and cut it in half, you'll get a 180mm diameter port that is perfectly hemispherical, but if you take a 400mm diameter sphere and lop off a section that is 180mm in diameter, this will be a fairly shallow bowl. Lenses with wider fields of view, particularly fisheyes, work better with steeper curved domes.
SeaFrogs, being the budget manufacturer, don't go into all this detail. If the lens physically fits into the dome, that's good enough as far as they are concerned. With one exception (which is only really applicable for surf photography, not underwater work), all of their ports have a built-in, fixed extension, and thus are more-or-less optimized for one or two lenses, whereas everything else, while it may or may not physically fit inside, will be hit or miss with regard to image quality. Also, the largest dome that they have is an 8-inch model that is really closer to 7 inches in practice, which is borderline acceptable for 16mm on full frame, but nowhere near good enough for 12mm, especially in light of the fixed extension.
