This is something I have taken with me during the early games of Civ (think Civ 2) where you could lock the tech era's during a custom game. If this isn't possible possibly making tech way more expensive. My hope is this will be doable in the modding capabilities in Humankind. As it sits tech is really cheap, even during the endless pace in custom game. I am finishing the last cople dozen techs in 3-4turns a peace!