I've made my spot position plotting scripts much simpler to use, and put them in the svn folder that holds the A2L scripts.

The script to open, modify if needed, and run is /opt/rtcds/userapps/release/isc/common/scripts/decoup/BeamPosition/Run_A2L_plotter.m

This script calls 2 sub-scripts.  The first one (GetA2Lspots.m) will go through the data in ..../scripts/decoup/rec_LHO/ and pull out any measrements that have been taken since the last time this was run.  It will calculate the resulting beam spot positions for the test masses, and save the data.  The second sub-script (PlotTestMassSpotPositions.m) is just a plotter, for which you can change some parameters (start and stop time for the time axis, etc) in the Run_A2L_plotter script.  Or you can just run each script individually, using the Run_A2L_plotter as an example. 

I haven't yet added a few fancy options that I'd like, such as the option to plot the O1 or O2 average spot positions, but the basics are there.

I didn't check in our A2Ldata.mat file, but the scripts are all in the /opt/rtcds/userapps/release/isc/common/scripts/decoup/BeamPosition/ folder.