Can you recommend me good novels where the MC can travel or bring goods from a fantasy world to Earth and vice versa. Bonus if the MC doesn't just bring and sell them, but also experiments with new tech and combo of magic and tech. Something like The misplaced Dungeon on RR is also in that category.
I Have a Mansion in the Post-apocalyptic World - modern and fallout-esque world Outbreak Company - turns fantasy world creature into otaku
Takarakuji de 40-oku Atattandakedo Isekai ni Ijuu Suru Netooku Otoko no Tanoshii Isekai Boueki +1 for this
“Cub Raising Association” has a bit of Earth to sci-fi world transfer, but it’s barely a part of the novel at all.