A feature I think could be useful for longer flights is if the fuel quantity was fixed once in flying mode. But to have the ability to enter en-route fuel at intervals as required/desired and have the GPh updated. So perhaps you enter fuel mid leg and you get a prompt like "your aircraft profile is set to 9gph. You're using 11gph. Skydemon has corrected your estimated fuel remaining for this leg. Would you like to apply the new GPH for the rest of the flight?".

I'm only talking about what you mightdo with a paper plog in terms of monitoring fuel burn.  I wouldn't saypoor planning. Just diligent monitoring

But thats a fair point. 

well, another way around would be to check fuel vs. expected remaining fuel. This would give an idea if your consumption is below or higher than expected. You can add a column with remaining fuel in the plog.

Hope this helps.