Z-bend spokes have some attraction but
a) you have to be able to make them to start with (which requires spokes at least 10mm longer than the target spoke)
b) once fitted, such spokes can't be properly stress-relieved (because loads which give good stress-relief will straighten the Z bend)
c) you still may (e.g. in a SF hub) not easily be able to fit a Z bend spoke through the RH side of the driveside flange.
The last of these may mean that the spoke can sensibly only be fitted from the wrong side of the flange and this means it approaches the flange hole at an even less favourable angle than normal. It is of some advantage to have a set of pliers to hand in order that the bend angle can be adjusted; this can make the difference between being able to fit the spoke or not.
Re b), obviously not every wheelbuilder stress-relieves spokes the same way but then again not every wheelbuilder builds properly reliable wheels, either. IMHO if you use a stress-relief method which doesn't tend to straighten Z bends, the wheel may not be fully stress-relieved (which might be why the spokes started breaking to start with) and/or this means that the repair is only temporary; you still need to do a proper repair later on, or accept that the wheel is not as good as it should/could be. [Were it otherwise, we'd all use Z bend spokes, all the time, surely...?]
So I guess a Z-bend spoke is a kind of halfway house, if you can fit one; it is a kind of "better but still temporary repair" ...?
In the grand scheme of things there are various options for when you break a spoke
1) do nothing except make sure the wheel clears the frame/brake;
2) slacken some of the spokes on the other side of the wheel
3) some kind of temporary repair
4) a proper repair
Either of the first two are often enough to permit a day's ride to be completed. A temporary repair is of attraction if it is quicker to do and/or will allow a longer period of use (eg several day's ride at least) before a proper repair is carried out. A proper repair is often the best option in terms of net effort.
It seems a fair number of touring riders either don't worry if their cassette lockrings are not very tight, or indeed deliberately have them set somewhat loose, reckoning that this does no real harm and allows easier driveside repairs to be carried out should the need arise. I'm not convinced that this is entirely harmless (I've seen rather notched steel freehub bodies, even) but it may be a reasonable compromise if some kind of 'cassette cracker' is to be used; some of these tools can put very high loads onto the dropout if the lockring is tight. I have often wondered if there is a different approach.
For example if the lockring can be sufficiently strong/secure (that it doesn't itself back out or allow sprockets to move) but can still be undone easily if required, using something that is not a specific splined tool, but something more general. I have wondered if simply grinding a notch or two into the periphery of the lockring would leave it fit to do its job but also allow a simple drift to be used on it (with the wheel in the frame and a low gear selected). I would expect a suitable drift to fit in the gap between the smallest sprocket and the frame dropout. I have often carried a 4" long flat screwdriver bit in my touring toolkit and this might be all that is required....?