While working on my term paper, I suddenly realized that some differences between UEB and Unicode that I thought were there aren’t really there. Mind you, that still doesn’t mean Unicode can be reliably converted into UEB: I still don’t think the process is reliable. There still are discrepancies in semantics, and there still are cases where human judgement (or very good artificial intelligence) is required. Sure, the specific example of gross incompatibility that I thought I observed isn’t really there; but, as far as I can tell, there still are incompatibilities.
I should not be doing this at such a time in the semester, but I kept the screen reader running for a few hours today, and I found, to my dismay, that the answer is no. A system-provided screen reader is not necessarily stable. The first program to fall victim to instability was Terminal. It started crashing for no apparent reason, and at one point it repeatedly crashed after less than a couple of minutes of usage. Terminal and VoiceOver do not play well together. The second program to fall victim to instability was Safari. After a few hours of screen reader usage, Safari started to stop responding to tab switching. Turning VoiceOver off immediately fixed the problem. Turning it on caused the problem to resurface after just a couple of minutes. If such is the stability of a screen reader built into the OS, I wonder what kind of stability third-party screen readers on other platforms can really achieve.