I am with greybeard, not worth the risk to water bath any low acid veg. Also I like the more firmness of the frozen. I do the french cut style, if the bean gets a little big and the seeds get a little big inside, the frencher will slice them into thinner strips and the bean inside gets sliced up too. The pieces will get left behind in the water when blanching. I have done both blanching and not, in the past and have found that the blanching makes the beans taste better. I believe it is from the stopping of the enzymes. Plus gets any bugs or worms and leaves them in the blanching water... As for the self defrost freezers, they will affect the quality of anything in the freezer by the very nature of removing the moisture. I only vacuum pack anything now that I freeze, and that stops the possibility of dehydration or freezer burn unless you get a pin hole in the bag. I have some vegs that I froze in 2013 that I found and they are nearly as good as the day they were frozen.
One thing also that I think you are not taking into consideration, freezing causes the cell walls to rupture so the green beans' cell walls are not as intact when they are frozen without blanching. So the product is also a little mushier once it cooks. If you heat after freezing the water in the ruptured cell wall leaks out leaving a less firm product. If you blanche it first, the heat does a different altering of the cell structure, and then when freezing after, it does not cause the cell walls to rupture, so the water does not cause the mushiness of the bean. I don't have the scientific explanation but that is the basics.
CG8, it doesn't matter how "dirty" the vegetable is, there are bacteria that are not visible. So blanching will also destroy any unseen bacteria that could lie dormant on the frozen green bean , which can cause it to degrade once defrosted. If the bean is eaten raw directly after washing or even from the garden directly, the bacteria is subject to your stomach acids and the heat that is generated through digestion. It is often rendered harmless that way. Greybeard is right on that also.
Also, any meat has different types of bacteria, and no one blanches it because it is usually cooked after thawing. The difference is that freezing does not affect the cell structure of meat like it does vegetables, so it is as much for quality of the bean as for the food safety/bacteria issue also.
I am wanting to try the freeze dried vegs if I could find someone who has one. I like the idea of not having to have to depend on the freezer in case of power outages. A generator is great but if you run out of fuel...you are out of luck. The freeze dried stuff would keep for years like canned stuff, and take up less space. I can most of my fruits, and have eaten them years later as long as the seal is good.
I have used the tattler lids for several years, they are great and once you get the hang of them, will last. The rubber gasket is also reuseable if you don't accidentaly cut it while unsealing a jar and they are not that expensive to replace. I also use the old style canning jars with the glass bail tops, and jar rubbers. They also are good and if the lid is loose, the food goes in the compost. It is nice to have alternatives to the metal lids. I have reused metal lids occasionally, mostly on things like jelly, although I do not process the jelly like they now recommend. I can remember when we used to seal the jelly jars with paraffin (wax).....