You can. Until you end up with a system where you can no longer remove directories where directory names were manipulated without UNICODE.SYS being loaded. That messes up the unicode character string on a very basic filesystem level. And then, DFSee is your last resort to rectify that.
If you always use en_US locale, you will very likely NEVER run into this problem, because codepage 437 is the default for about anything that relates to an ASCII string in OS/2. This is about people that either have to use a different codepage or where the OS installation installs a different codepage as the primary codepage. For a german OS/2, codepage 850 is installed as the default (with 437 as a secondary codepage) even though codepage 437 would also do for most of the things (german umlauts are also supported with codepage 437 and even have the same byte value as in codepage 850).
In short, for a few special characters, codepage 437 and 850 are identical. For the lower 128 characters, 437 and 850 are also identical (and that includes 0-9 a-z A-Z : \ .).
For a french codepage this will be comparable but certainly not for any cyrillic codepage.
Which also makes it clear why no modern operating system is using codepages anymore.
I repeat: this is an absolute NOGO for a commercial operating system.