I can see the convenience for camping or taking to work. But if you are home, why not just cook them in a pan? I'd rather clean out my nonstick frying pan than try to get eggs out of a jar or a bunch of ramekins. You could still mix everything up the night before and just pour in the pan in the morning if that saves time. And of course there's always the breakfast muffins, which are basically the same thing and can be made up in advance in quantity and warmed quickly in the microwave. I'm all about efficiency, plus there are the environmental and health factors with the plastics. Just my 2 cents.
There are plenty of boil-safe bags on the market, and if you have a vaccuum sealer you probably already have the right kind of bags (you just have to seal the bottom add the eggs and then seal again. Camping supply stores, and many large grocery store chains will also have "boiling bags." If not, cooking bags would probably be safe, but you'd have to tie the end very well to prevent seepage.
I see nothing wrong with using the Ziploc freezer bags once or twice a year for this but I don't think I'd do it all the time. It does have to be heavier bags like the freezer ones. The steamer ones mentioned here sound interesting.
I've done canning but my canning jars fit into a rack that gets lifted carefully into the boiling water and lifted out. I doubt if it would be worth the trouble for eggs. But you can make wonderful dill pickes.
What I do is use the little Pyrex ramekins. My microwave has a breakfast setting for scrambled eggs. I tell it how many eggs (or Eggbeater equivalents) and then it tells me when to stir. It is easy and makes it a good shape for putting on toast. The bags are better for tortillas.
The bottom line for me is how many I am cooking for. I think we had over 150 for last year's Webelos overnighter.
These particular plastics are known carcinogens, and there's no known "safety threshold." Even the Ziploc website directly advises against it specifically.
I have a friend who swears by these, and got a bit upset when I pointed out that she avoids artificial sweeteners and preservatives (which most of the research suggests are safe, ar at worst "uncertain") and yet is ingesting a known carcinogen fairly regularly.
Considering that "boil in bags" are readily available, using unsafe plastics just is not worth the risk.
While I wouldn't cook in the plastic bags (tho it sounds awesome), you could freeze these and put the in the fridge the night before to defrost and make in the am. I have a few of those cook-one-weekend-eat-4-a-month.
I know so little about cooking eggs...
