I've been an Albin guy for a long time and for many years very active in the Albin Owners Group Forum, purchased a 2002 Albin 28TE Engine Box model in 2004 and ran that boat for 9 seasons.
The original Albin 28TE engine box models with reversing gear had this small rudder. Due to lack of slow speed handling the rudder was squared off and the boat then handled quite well at all speeds. Rudders were provided by Buck Algonquin.
Fast forward to 2005 when the market place demanded a more roomy cockpit and Albin introduced the "Flush Deck" model. To achieve this, Albin needed to move the engine forward and raise the deck about 6 inches. The dance floor was achieved and the marketplace was thrilled. Another win was that with the engine forward the reversing gear was eliminated. The downside: access for service was a bear and steering at higher speeds with the larger rudder proved quite squirrelly with the bow taking nose dives when cornering. I was at Standish Boat Yard in Tiverton, RI when Albin was there sea trialing different methods for correction as this hull was never originally designed to have a "Flush Deck". Albin started with 50 gallon drums of water on deck shifting them around to try and re-balance the boat, adding pig iron and ultimately cutting the improved square rudder back to what is pictured in the OP's opening to this thread. With the cut back rudder the high speed handling was improved with no more nose diving in the corners. Unfortunately, the Flush Deck can't corner as sharply as the Engine Box Model. It's not ideal, but it works.
The short is that the original Engine Box model is a much better handling boat, but the marketplace demanded the open cockpit and compromises were made.