I don't know if someone has come up with this before, but I've started thinking about how fun it would be to throw Senku into an isekai. I've been bored to death of traditional power fantasy isekais and considering his bad luck and power balancing, I think it would be funny if he had ridiculously low mana and can only manage level one spells. As such, I think Taiju would probably be the hero they were trying to summon, but they either missed and got a wimpy nerd, with Taiju and Yuzuriha making Senku's main goal to find a way home, or they end up with the full trio, with Byakuya being his motivation. Tsukasa would be a summoned hero that went AWOL after defeating the first great evil, though it is eventually revealed that he was promised a ticket home in exchange for defeating it and was told that it was impossible afterwards, causing him to shun the royal family and nobles, rather than adults in general. He quickly joins Senku after finding out about his end goal so that he can see Mirai, again. Gen and Ukyo are both reincarnaters, with Gen being a really powerful black mage with memories of a life in a third world and strong spatial magic, which is necessary for a portal home, and Ukyo being some kind of a white mage or ranger with memories of his life on Earth. Kohaku, Ruri, and Suika would be princesses to a neighboring kingdom, and Ibara would be the person who summoned Tsukasa and Senku. Ryusui and Sai would probably be the sons of a duke, or something. I think Suika would eventually gain memories of a prior life like Gen and Ukyo, but only partway through the narrative, mirroring her aging during the South America arc. Chrome would be a random peasant kid with strong earth magic, which Senku would need for materials and quickly joins up with them. At some point, they probably end up overthrowing Ibara, making Tsukasa really happy, and giving them political power in the process, though Senku would refuse to become king. Halfway through, they manage to make an interdimensional telephone, allowing Senku and Tsukasa to contact Earth. I'm thinking about the potential of time dilation between worlds, so Ukyo might not have anyone to contact, and Gen and Suika's dimension was destroyed and partially merged with the current one, creating the so-called second 'great evil', so he wouldn't have anyone to contact, either. But yeah, random thoughts.