Thanks for playing and taking the time to comment. Currently the saves only track drone upgrades and not drone numbers, so it really more of a feature or rather a lack of one. I think it's a good point though and maybe it would respect the players time better if the game did save that. I did have an early build where the player could select specific targets for their miners but it made some of the other advanced drones redundant and I also feel it took away from the strategy a bit. Balancing does seem to be a sticking point and I do plan to address this by separating the unit costs into their own categories.