In testfix for PIM, there is the tool called tfinstall.exe to apply testfix. Does the tool check file version for the files in the testfix to apply testfix?
No, the tool which is currently included in testfix doesn't check the file version. So even if the files in the testfix is older than the files which is already applied, it is applied. This is current design. However, In the future the new tool will check file version and apply. The new tool will be included in testfix.