I have both wide angles and extension tubes in my bag. I have tried several times to use them altogether. With some of them, you can’t focus even with the thinnest extension tube. Indeed, the shortest focus distance is already extremely close to the front lens for most of the very wide angles. E.g. for my 16 mm, 20 mm and for my fish-eye: at the shortest focus distance possible, the object is almost on the front lens – the distance is no bigger than a couple of cm. There is basically no need to add an extension tube. But with 24 mm, or longer, it is working perfectly.
That said, I have failed to find a reason to shoot at 24mm + extension tube when you can shoot at 20mm without extension tube and have the same result with more flexibility in the range of focus.
Indeed, it is important to keep in mind what’s the point of using an extension tube for a wide angle. Basically, two things: being extremely close of the macro object (1) and (2) get some context beyond this macro object (from the background). I see very few reasons to shoot with a wide angle lens + extension tube like you would do with a standard prime and cheap 50 mm but to add problems you don’t have with the 50 mm (lighting in particular or just because you are so close to the macro subject, like any bug, it may fly away).
When you want to be close to a macro object whilst getting some context from the background, you should not be worried too much about lighting the object. Of course, it can be a challenge like for any macro shot but nothing specific. Indeed, I would use natural light from the background anyway, that I need to capture as well, that’s the reason to shoot with wide angle at very close distance as explained.
To summarize, if I had no very wide angles (20 mm or shorter) but only 24 or 28 mm, I would say extension tube make perfectly sense for macro with background. But if you have shorter lenses, I am struggling to find value for extension tubes on wide angles.
Image shot with a Nikon D7000 + Fish eye 10.5 mm. The butterflies were as close as 2-3 cm maximum from the front lens. No extension tubes. From https://www.flickr.com/photos/tristanromain/16175832981/in/album-72157627481877415/