Thanks for the feedback.
As far as the size of the chessboard is concerned, I'm afraid this is hardcoded in the code at the moment.
In order to add chessboards of different sizes to your joomla articles you have two options:
1) tweak the plugin code.
Look at the file embedchessboard.php where the square size is set in the line:
$replacement .= "&ss=26&ps=d&pf=d";
Changing the square size number "26" to a larger number will make your chessboard larger. You will also have to change the portions of code where the variable $height is set in order to take into account the larger resulting board size (manually increase the height numeric values and check the results on different articles showing different chessboards). When increasing the square size, the plugin will also look for larger piece bitmaps that are not in the package and that you will have to add manually from the main pgn4web zipfile available at http://code.google.com/p/pgn4web/downloads/list
To help you in this complicated process, you might want to look at the work done by the user contributing a backport of the plugin for joomla 1.0; within the backport he also added the option for different board sizes. Look for the joomla 1.0 plugin at the joomlacode download page:
2) use a generic plugin to embed iframes.
Alternatively, lot more chessboard configuration options are available if you install a generic plugin to embed iframes in your joomla articles, such as this one:
Then you generate the iframe src parameter from the pgn4web board generator tool available at:
Be aware, neither of the 1) or 2) option is as straightforward as using the basic plugin, but both would give you the flexibility you want.
If I get a lot of user requests I might add the option to tune the chessboard size... but don't hold your breath.
Thanks again for the feedback.