If you made other modifications to the scripts then the three already listed, can you document them here?

I've been trying like crazy to modify this script to convert SMF 2 to CBB 4.

My brain is about to explode.

I can't go backward on the SMF 2, but I could go back to an earlier CBB version.

Has anybody re-done this script or are there any suggestions?

I would like to change from SMF to Xoops, but there are 6,500 users at the current SMF site and I don't want to have to start over from scratch.

Wait for CBB 4.0 Final and use 3.08 for the time being.
As you see in the thread, some adaptation for the scripts are required to make the number of fields correct for some tables.

I think the other huge issue is password hashing.

If you modify the Xoops script heavily to allow SMF passwords, then you are forever stuck with having to try and modify each and every new upgrade to Xoops.

I have kind of come to the conclusion that there is no practical way to handle this unless you want to spend a great deal of time making the transfer only to have an incompatible password system that will cause future problems.

I've been playing around with trying to get these scripts to work with a SMF 2 installation.

I have found that SMF (without much point) changed around their database to make most things lower case and the order in which fields are in the database have changed. So, you have to rename fields to the proper case and/or with underscores.

On top of that, there appears to be quite a few more fields in the members database. So, it is a matter of also having to try and match:

What order things are in
whether upper or lower case
whether SMF gratuitously threw in a underscore
what fields will match the right Xoops fields.

I really don't care about many of the fields, like URL, ICQ, aim and so on. Is there an easy MySQL syntax to let the script skip lines that do not match?

All I really want to do is get those SMF "members" into the equivalent Xoops "users" field, along with posts and other essential information. All of the user's personal information can get lost for all I care.

This script runs down to a SQL select all from the SMF user table. The fields of the resulting array are then inserted in the XOOPS user table with an SQL insert.
INSERT INTO $xoops_users VALUES ( list of values)
The list of values has to have all relevant fields from SMF and literal values for the other XOOPS fields. The list has to be in the order of the XOOPS user table (see structure).
By specifying a field list
INSERT INTO $xoops_users ( list of fields) VALUES ( list of values)
you could rely on the default clause of the table structure, if this value corresponds to the value wanted.
This way you can shorten the list of values (same length as list of fields).
However some fields as eg activated will need a dedicated literal value.

Alternative is to convert the tables with phpMyAdmin and full SQL
INSERT INTO xoops_users (xfield1, xfield2, ...) SELECT sfieldx as xfield1, 'literal1' as xfield2, ... FROM smf_members