I found a
document by Connectix that "MODE32 is provided free of charge courtesy of Apple Computer through a special distribution agreement with Connectix Corporation."
Reading further in that document about MODE32, Connectix cautions:
It will enable Macintosh II, IIx, IIcx, and SE/30 computers to use standard System 7 32-bit addressing. It is not functional on other types of computers.
Some applications and INITs are not "32-bit clean". That is, they are incompatible with 32-bit mode. Such software will usually cause your system to crash immediately when run in 32-bit mode. When you need to work with any non-32-bit clean INITs or applications, we recommend using MAXIMA. MAXIMA extends the addressing of your physical memory to 14 megabytes without resorting to 32-bit addressing, so it is compatible with all applications.
Please remember that when running in 32-bit mode, all of the INITs, devs, and application software you use must be 32-bit clean.
So, the Macintosh II, IIx, IIcx, and SE/30 computers with 32-bit addressing enabled using MODE32 may crash if a 24-bit program is accessed.
Some articles from TidBits provide historical insight about customers' whole 24-bit/32-bit furor and Apple's lack of solving the problems that Connectix helped to solve. IMHO, bandaids.
Using modern ROM SIMMs seems to be more appropriate and manageable.