Let me recommend another super CONFIG.SYS
DOS=HIGH,UMB,AUTO
DEVICE=C:\DOS\HIMEM.SYS /TESTMEM:OFF /Q
DEVICE=C:\TOOLS\UMBPCI.SYS /I=DC00-EFFF /F
DEVICE=C:\DOS\EMM386.EXE FRAME=NONE X=DC00-EFFF X=B800-C7FF I=CC00-DBFF I=B000-B7FF RAM M3 D=256 AUTO
XMS is controlled by HIMEM.SYS, EMS is controlled by EMM386.EXE, while UMB is controlled by UMBPCI.SYS and also shared with EMM386.EXE. If removing FRAME=NONE and changing DC00-EFFF to D800-EFFF doesn't make it crash, then you'll get a bit more memory this way...
However, UMBPCI can never reach 631K available memory (at most only 630K, usually 628-629K). If you need that, you still have to use QEMM386 + LOADHI, but the compatibility is too poor.
Somehow somewhere I've got to choose.
No matter if it is win or lose.