I think the benefit here is that the fins and the alloy material will promote better oil cooling. Possibly offered as an accessory to the general public and-or for production racing.
The benefits of dry sumping an engine are more applicable to higher revving engines than the Triumph- lower losses from the crank thrashing around in a pool of oil,better control over oil distribution, and less problem with aeration of the oil. Also can allow the engine to be mounted lower to lower centre of gravity. I am not aware of any TR's that had dry sumps, but would be interested in being corrected on that point.