I think you choose wrong mob in setup. If I switch to Apex Eruca I get this:
Which is close to what you did in video (22899 DS crit on start of the video is 1.5% lower and 14526 normal crit in ~18th second of the video is 2.5% lower).
Some small difference will always be possible, because of many rounding that happens in those calculations and you are Elvaan too, so you will have slightly higher fSTR2 (because of slightly higher base STR than I set in calc) on mobs where fSTR2 is uncapped. Also lvl of Apex Eruca will change damage slightly too, because their VIT varies by quite a lot even with 2lv difference.
EDIT: When I test stuff in practice (like crit damage or double shot damage) I usually get like 0.998 instead of full 10%. If you get something like that in something as complex as max crit that include (true shot%, double shot damage+ %, Dead Aim %, Crit damage%, PDL%, etc.) damage on paper will always be slightly higher and I dont think I can make it more accurate, unless I would start guessing what % stats I should lower by fractions of %. You can also just assume, that in practice numbers will be like 1-2% lower.
Edit2: Also
thanks for testing!