you can possibly use tomato paste to reduce cooking time or use a mixture of tomato paste and diced tomatoes, if you find the green beans are too cooked (more in the style of curry to use the tomato paste).
It may also be interesting to stuff it under the broiler if someone figures out when. I get annoyed at veggies being too cooked and I feel like the tomato sauce reduction might take too long.
i.e. blanch beans, fry fast with garlic oil, add tomato paste and a little bit of diced tomatoes, perhaps broil but I am not sure.
It would be a different dish with the same ingredients, but I do appreciate the fact that there is no complex steps in this recipe, so it might actually be made. Given the extreme shelf life of all the ingredients and the ease of cooking it seems like a great backup meal to unhealthy food that would normally be made with the same effort, since green beans last forever ( I don't mean the canned ones, I just noticed wow.. they can lay there for a very long time compared to everything else I normally eat).
I think that you make some good points. First, it is a simple recipe and that, in a sense, invites modifications - nothing wrong with that, in fact, that can put some fun in the process, even when it ends up a different dish..
I'm really not much of a cook. I do know how to make a handful of dishes and, now, they almost always turn out well and the way I intended, but that is because 1) I have made them many times and 2) they are often dishes that I grew up with so I know how they are 'supposed' to taste - even if I introduce some modifications.
The tenderness and cooking times of these green beans can vary significantly. In my experience, good quality, fresh - as in a vegetable stand where the seller is the grower - cook faster then the microwavable, organic, save the earth (instead of save our asses because the earth can take care of itself) bag of green beans which have probably been hanging around for a while. Even without that factor, there is a lot of variability (larger is usually tougher and needs a longer cooking time) and tasting is the test for when they are done (that is one reason why the sauce gets going first, because you can add a little water if you have to lengthen cooking time and uncover the pot if you need to shorten cooking time - these, to keep the sauce 'right').
Concur with some of your suggestions also, save the broiler because now you are getting back to casserole territory