Him being very plain is entirely deliberate. He's designed to be... pretty much the polar opposite from your traditional anime characters -and isekai protagonists in particular.

He's not a teenager with delusions of granduer, or someone who has spent their entire life playing/reading/watching things which would prepare him mentally and intellectually for this kind of situaton. He's a farmer; strong and worldly but not well educated or informed on modern culture like anime and manga.

Throwing a character with a lot of real-world skills into a fantasy setting for which he is wildly unprepared is pretty much the idea I had from the beginning. Especially since he's an adult, they're not as good at adapting to a sudden change in environment as teenagers are. There's a lot of development to be found in him learning how these things work. It also encourages him to interact with the younger crowd who have a better comprehension of what's happening.

Admittedly, I would like to write a more extensive sheet; but because of the type of character he is it's kind of hard for me to bulk it up without going into obnoxiously specific detail about stuff like how he names all of his livestock animals and will whoop the ass of anybody who mistreats them.