This may be a long shot, but I'm aware that you can set your start transaction in the first screen (Extras >> Set start transaction) so that when you log on you are automatically in the required screen instead of the SAP Easy Access screen.
But if there are 2 transactions you always use, is it possible to get SAP to load up one transaction and open up a new session in another transaction as soon as you log on?
Any feedback would be greatly appreciated.