It is probably wise and may be necessary to get a new Mod compatible with v1.01 rather than use the old Mod. Each BFF archive has many files in it some of them may have been changed by the patch and for a particular Mod you only want to or need to change a single file in a BFF archive. Using the old Mod BFF would replace possibly changed files, I don't think that's a good thing.
It's not too difficult to prepare a new v1.01 compatible Mod. It's even not too difficult to do it yourself. All the tools are easily available.
I use BFF Tools
(original programmer's version BFFTools
) and WinMerge
to look at and compare the files. You don't need to know what you're doing, you just need to know what to change.
Don't unpack the whole game, just the one BFF (or more) archive that contains your needed changes.
Use BFFInjector, it really works and is easier to use than repacking the whole archive, that way you usually are only working with one file instead of the whole archive. Actually either way works fine.
WinMerge can be used to compare entire BFF archives (compare the folder) once they're unpacked. This is useful to compare an original BFF with a Mod BFF to find out what contained files have been changed. Even slightly more useful if you happen to have the v1.0 files.