Also it's not technically an isekai, but I highly reccomend checking out the series called "Zipang"
I've had difficulties finding it on any streaming sites before, so you might have to download it from something like Nyaa(.)si
But short synopsis: The Japanese Navy sends out a battle ship for a routine mission, but somehow the ship where our protaonist is aboard slips through time and are faced with a plethora of moral and ethical dilemmas due to the reality they're plunged into.
And also, just for an extra layer of motivation, take a listen to this OST: