Hello @SimBrief, and Happy New Year.
I just noticed that support for Ops Spec B343 fuel reserves has been added. I’m happy to see that the development is going down the path of adding other FAA reserve methods so I ran a few flight plans to check it out.
I’m not sure what method you are using to do this, but for me the math isn’t working. 
Under the “OLD” B343 the enroute reserve was calculated at a FIXED 5% of total enroute time, with a final, or destination reserve of 30 minutes at holding speed 1,500 feet above the alternate, or destination if no alternate is required.
The “NEW” B343 is Performance-Based Contingency Fuel, which means the enroute reserve is now a VARIABLE percentage of total enroute time based on direction-specific city pair, arrival time window, and airframe type along with the previous requirement of a final, or destination reserve of 30 minutes at holding speed 1,500 feet above the alternate, or destination if no alternate is required.
This becomes much more complex requiring a lot of data points. For simulation purposes though this value could be set by the user.
I don’t know if the proper display is OFP format specific or not, but I tried the LIDO, AAL, and AWE formats and they were not displaying proper fuel calculations for this Ops Spec.
If any SimBrief programmers would like to reach out I’d love to help get this sorted out to where the calculations are following the correct rules. I’d also like to see Ops Spec B043 Special Reserves and Ops Spec B044 Redispatch added in the future.
And as a side note, the AAL OFP format isn’t correct for domestic flight plan use. 
Respectfully,
Mike Collier
Flight Dispatch Training
American Airlines