A tiny bit can be gained by lowering FILES and BUFFERS but I don't see the need. You should not have any memory issues with these start-up files. Even Ultima VII works fine with menu option 3.

Now if you're using MS-DOS 7.1 (The DOS that comes with Windows 98) then you will have less memory. It's just the nature of MS-DOS 7.1.

For things that don't use expanded (EMS) memory, availability of upper memory for loadhigh/devicehigh can be increased by using the NOEMS parameter on EMM386. It may be needed for those "last straw" situations.