My method ended up being unstable. I experienced infrequent crashes, but there were enough of them to let me know something was wrong.
I'm trying the Magic Memory Upgrade Mod. I'm on my second attempt. The first attempt froze on this step (A progress bar appears. ~~~ Data is being loaded into RAM. This might take a while. ~~~) for four hours. I got the Clara to reboot to the install on the original SD card, but my second attempt is turning out the same.
How long is this RAM loading stage? Did I abort too soon? Should the Clara screen be frozen on the progress bar?
And since I have the other expanded SD card on hand still, what reasons might cause random crashes on a new SD card in a Kobo? Maybe this isn't an install problem at all. I should state, however, that the original SD card had no crashes. I just don't know enough about this process to reason what could be amiss. Thanks for your input.