Traveling back in time to the ancients doesn't have to be earth-shattering, it can just be a homely experience.
It's not necessarily bad to travel through time into an ugly person, and it can make living in a more smooth life.
When you travel to a princess, you don't have to love the prince, you can make the prince fall in love.
Above, the cannon fodder heroine, the main character is probably a bit silly and a bit white, but I won't let her be white until the end.
I hate sadistic writing, so there are at least some twists and turns in the middle, but never sadistic.