The root post was updated with a new version of each script package that adds a check for $src:autosize... so the script can now work off of both lister and source tab specific variables. See what you think... And since you mentioned dual display listers, if someone thinks they might want linked tabs or dual-display tabs not linked but running under Navlock enabled, let me know if you want an additional change to have both sides auto-size. I' haven't tested the script in dual-display mode yet... not sure what will happen, but I expect it will work with the LISTER variable toggle button, but I think some more work might be needed to get it to to auto-size both sides of the lister with the new source tab option.
About your other question, the reason the toolbars vertical height increases with AB's triple-button is because the second child-button (Relative Size) has it's label state set to Default. Setting it to show on the Right will fix it. This happens to be related to a pet peeve of mine 
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