Renewables proliferation in the energy market is driving the need for flexibility in gas fired power plants to enable a wider and emissions compliant operability range. The ability for a gas fired plant to peak fire while maintaining emissions compliance, full life interval capability, improved simple and combined cycle heat rate and the ability to achieve extended turndown, positions a gas fired asset to benefit from an improved capacity factor, and overall economic viability in an increasingly renewables’ dependent energy market. The low pressure drop FlameSheet™ combustor variant’s implementation alongside PSM’s Gas Turbine Optimization Package (GTOP3.1) on a commercially operating frame 7FA heavy duty gas turbine in 2018 and as introduced in GT2019-91647, is presented with emphasis on extended validation of operational and emissions/tuning performance at different ambient conditions, higher peak firing and minimum load after one year of continuous commercial operation. The output and heat rate improvement achieved with the FlameSheet™/GTOP3.1 conversion thus enabling improved capacity is also discussed. As shale gas continue to grow as a dominant source of the U.S Natural gas supply, the need for fuel flexible combustion systems enabling tolerance to higher ethane/ethylene concentrations associated with Shale gas is required for improved operability. The adverse impact and means to mitigate such higher ethane/ethylene content on standard F-Class heavy duty combustion systems is also presented as part of said FlameSheet™/GTOP 3.1 conversion.