sortUndefined and Excel like sorting

TanStack Table version

8.21.3

Framework/Library version

React 18.2

Describe the bug and the steps to reproduce it

Hello and thanks for that fantastic library! I have a question or a bug when creating an Excel like sorting. My problem is to get the null/undefined results always to the bottom of the table. I would have assumed that sortUndefined would do the trick but it did not. Therefore I tried to create a custom sorting for that. But I can not manage to geht the sorting correct. Correct (Excel Like) would be, if my table could do that

Excel Behavior	Supported in excelSortingFn?
Numbers before text	✅ Yes
Booleans in correct order	✅ Yes
Case-insensitive strings	✅ Yes
Empty/null values last	❌ Problem
No coercion of string "123"	✅ Yes

I added a simple code sandbox link below to try it out. Any help would be greatly appreciated.

Your Minimal, Reproducible Example - (Sandbox Highly Recommended)

https://codesandbox.io/p/sandbox/boring-ellis-sw7h86

Screenshots or Videos (Optional)

No response

Do you intend to try to help solve this bug with your own PR?

No, because I do not know how

Terms & Code of Conduct

• I agree to follow this project's Code of Conduct
• I understand that if my bug cannot be reliable reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.