Maybe I'm going crazy, but I remember EGA working, but now it seems that no matter the machine class I choose, xt,286,386,486,pentium (with/without jit) it hangs when I select it, then just crashes.
MD5 of the rom:
0636f46316f3e15cb287ce3da6ba43a1 ibm_6277356_ega_card_u44_27128.bin
I recall being able to install Windows in EGA mode, but no dice of even getting a VM to POST.