If you follow the flight plan and it’s instructions you will have a trouble free flight. I also use IFAssistant so that I can program in the step climbs. Since I started using both I have never had a problem with long hauls.
I’m sure the majority of the community is getting their flight plans from FLPtoIF or simbrief. If you monitor your flight well you shouldn’t have any problems.
Ah yes I knew that’s what you meant, that bit gave me a double look too while transferring my TOC’s TOD’s on a piece of paper. So basically just follow what it says regarding when to climb or descent but use your best judgement: don’t go 250 KIAS below FL100 like it sometimes says and you’re good to go :) hope that helps, cheers!
My brother-in-law who an A380 pilot told me that he can start at FL370 (heavy) and finish at FL410 (lighter). There are tables to lower fuel usage. In real world they take care about winds.
SimBrief + FPLtoIF would help.