Sorry, but this is ridiculous.
If JFS.IFS can easily fail in a catastrophic way, then it is necessary to prevent that or at least to mediate the risk.
A new user would have no clue of what is going on. But maybe everyone has already accepted that there will be no new users...
Anyway, after thinking about it a bit more:
JFS.IFS can attempt to attach to UNICODE.SYS via a dehelp call and that can already be done on FS_INIT (call for initializing JFS.IFS) which is executed already on bootup.
If that attach fails you know that UNICODE.SYS is not loaded, display a warning message and even force the user to hit Return to continue boot process.
That takes around 10 lines of code in JFS.IFS.
But I am not the master of disaster. That is AN. They have the source code. And of course, it's closed source