At the moment, the HU to EU conversion rate for Stirling Generators is 2:1, which is equivalent to a regular-steam turbine set up. Considering the greater cost and engineering challenge associated with setting up a steam turbine, even just a regular steam one, the turbine should output at a better ratio then the stirling generator, so that there is a trade-off between the two and one can seriously consider whether they want to go through the effort of making a steam turbine for maximum efficiency or just go with a stirling gen for less efficiency but compactness and ease of set-up.
Therefore, I reccomend decreasing the Stirling Generator's HU to EU ratio to either 3:1, or 2.5:1.