How hard would be to make a higher robot tier, even if it's quite expensive i wouldn't mind paying for more base cargo capacity, speed and battery. Something like 5 base cargo capacity and x2/x4 base speed compared to the normal robots.

In my opinion, drones are already too cheaty and simplify the game.
There is also a problem with replacing old drones. When I played with B&A mods, I hated this process. Instead, it’s better to use "upgrade technology". So for example, in Krastorio was added technology for increase battery capasity.
It also seems strange to me when drones fly at the speed of a fighter.
Therefore, there will be no new drones, but the mod already slightly increases the cargo capacity of drones and their base speed. Also you can use other mods for new tiers.

Is compatible with Krastorio:
https://mods.factorio.com/mod/AtomicRobotsFixv

@Krastor Seems a completely fine reason to not adding new tiers also THANKS for the battery research tho I really liked that.

@Linver I'll check the mod, thanks in advance :)