@CrispyDragon do you have any new information according to that topic?
I've exactly the same problem with my ender 3. Standard profile in cura 4.5 and draft profile on cura 4.0.
4.0 calculates 8h 21 mins
4.5 says 14h 29 mins
And it also feels awfully slow. I can not explain where those addition 6h come from.